POLITICIANS OF all parties will be running scared in tomorrow's British elections. There is a sense of occasion heavy upon them--this is the first time in British history that a second general election in a single year has been necessary. But the politicians know that power and leadership is quickly passing out of their hands into those of the trade union leaders. And the goals of the unionists can be achieved no matter which party or combination of parties forms a government after the votes have been counted.

There are three major issues in the campaign: how the government will respond to the trade unions' initiatives; how the government will attempt to distribute the burdens of inflation and depression; and whether Scotland will continue to be an integral part of the United Kingdom. All three issues, however, resolve themselves into a single difficulty--Britain's slow-motion economic collapse since the second world war has made ever-present class tensions the most decisive factor in contemporary British politics. The Scots, meanwhile, want to dissociate themselves from the London government in order to secure North Sea oil profits, which they see as the solution to their economic problems.

Actually, this election will not affect these issues much. Neither of the two largest parties, or for that matter any of the smaller ones, are offering dramatic new policies; Britons face the same "choice" they have had since 1964: Heath or Wilson. Similar as these two sly, unadmirable men have always been, they have never seemed so indistinguishable as now--whichever one is elected will be powerless. The problems Britain faces are certainly not insoluble, but they outrun the imagination and power of any British government--and certainly any possible British prime minister.

Both major parties are pledged to a limited transfer (devolution) of power to an elected Scottish assembly, but neither are willing to grant economic autonomy. Both major parties are pledged to limit the inflationary effect of trade union wage claims by one means or another--the Tories place their trust in legal regulation and the Labourites in a formal but unlegislated "social contract" between the unions and the government. But neither party, once in power, will possess any means short of armed force to carry out its intentions. Both major parties are pledged to halt the staggering deterioration of British living standards--the Tories by fiscal austerity and wage-price controls, the Labourites by withdrawal from the common market and the wealth tax. This tax would produce a sudden increase in the living standards of the majority of the people by confiscating the wealth of the rich. But neither party can do anything about the worldwide pressures that make recovery impossible for an already weakened British economy.

NONETHELESS, the outcome of the elections will make a difference. If Labour wins with a substantial majority, we can expect to see the most plausible effort to effect a genuinely drastic redistribution of wealth ever undertaken in an industrial Western democracy. Labour is proposing a tax of up to 5 per cent a year on aggregates of wealth, about twice the level of Norway (the next highest one in Europe). In actuality the tax will be far heavier than any in Europe, since most European countries limit taxes to a set proportion of income. The 100,000 richest men in Britain could expect to pay more than 100 per cent of their annual income in taxes.

It is unlikely however that Parliament will approve such measures in their present form. The Labour leadership has proposed it only under intense pressure from the party's militant wing. Some party leaders no doubt intend to use the wealth tax as an election ploy--a voluntary wage-control program concealed as an attack on social injustice. Others may be committed to a genuinely new "social contract" between the unions and the government.

This contract represents an agreement to moderate wage demands that Wilson wrung out of the Trades Union Congress (TUC) last month. But some of the largest unions were publicly unenthusiastic about the contract. If elected, Wilson may find himself in a situation similar to the one in which he found himself in 1966, when he was forced to introduce wage controls after a few months in office.

This time around, though, he might not be able to enact controls even if he wanted to. Wilson's appeal rests primarily on his image as the one politician on friendly enough terms with the Union leaders to keep them in check. If Labour is in power, so the argument goes, the unions will not humiliate the government by forcing large wage increases. The Conservatives, on the other hand, will exacerbate the situation the way they did during the coal strike last winter. Wilson's power over the unions, however, has largely disappeared. Not only have the big unionists--like Len Murray, secretary-general of the TUC, Hugh Scanlon of the engineers union and Jack Jones of the Transport Workers--proved that they are the most powerful men in Britain, but most of Wilson's own party is now solidly behind them.

In the last couple of years, Labour has swung swiftly and militantly to the left. Since World War I, Labour party strategy had been to present itself as a political party just like any other party appealing to a broad cross-section of the population and not just to class interests. Herbert Morrison was the custodian of this vision of the parliamentary Labour Party, and since his death more than a decade ago the party has abandoned his position. Once again, Labour represents the working class, and, as far as it is concerned, its appeal to anyone else is purely coincidental and altruisitic.

IT IS NOT surprising, then, that the sudden, much-publicized resurgence of the Liberal party came at the moment that Labour reverted to its pre-war role--for it was the Liberal party whose constituency had largely switched to Labour ranks Under the photogenic leadership of Jeremy Thorpe, the Liberals received nearly 20 per cent of the popular vote in the election held last February. But under Britain's system of parliamentary representation they hold only 14 seats in a Parliament of 635. Thus the Liberals' chief hope for the future is proportional representation. Without it they can never hope to be a majority party and form a government on their own. Despite an imaginative approach that places them in between the Conservative and Labour camps and some well-thought-out proposals, the Liberals really have no chance of becoming Britain's majority party within the next five or ten years. Voter loyalty is too strong and the Liberals have yet to prove that a Liberal vote is not a wasted vote. The Liberals, it is estimated, must gain 30 per cent of the popular vote before the "take-off" point is reached where this large share will be realistically reflected in Parliament. If they fail to take off this year, they may be relegated once again to their role as political gadfly.

But the Liberals have another option, one that stands as the official position of the party leadership: coalition with one of the major parties to form a more broadly-based government, in which Thorpe would hold the balance of power. Actually, his position is less attractive since Wilson has ruled out a twenties-style Lib-Lab coalition and therefore Liberal willingness to join a coalition means a willingness to join the Conservatives. If the Liberals are to continue to receive the benefit of protest votes from dissatisfied voters of both parties they must insure that they are not too closely identified with either one of the major parties. For this reason, Thorpe rejected Heath's post-election offer last February to join the Conservatives. "The Liberals do not want a three-party system," one commentator has observed. "They want to replace one of the parties in the present two-party system, but they are divided over which one it should be."

SUCH A MOVE would be eased by the long-overdue withdrawal of Edward Heath as Conservative leader of the Opposition. Heath holds an honored place among the bankrupt political figures of the Western world. William Whitelaw, who did what he could in good faith in Northern Ireland and who appeals to the English sense of fair play, is an attractive replacement for Heath. But it is unlikely Heath will step down unless the election results are disastrous for the Tories. So far he has led a lackluster campaign and the polls put Wilson about 14 per cent ahead. Such polls, however, must be interpreted against the background of Britain's particular electoral system in which the location of swing votes is more important than their number.

It is difficult to see, in any case, why either party would wish to be in power and bear the "responsibility" for the events of the next 12 or 18 months--a period of time which will almost certainly see more hostility in Britain than any time since the General Strike in 1926. Smart politicians of both parties might be content to lean back and let the other fellow bear the brunt of the approaching disasters, then move in on a landslide to pick up the pieces. Perhaps this is part of the reason none of the younger, less tarnished politicians of either party have pressured their shopworn leaders into resigning--Heath or Wilson's last, greatest service to their supporters could be to serve as scapegoats.

INTO THIS complicated brew of motives and counter-motives is thrown the question of Scottish independence. Labour may be denied a majority not by the Conservatives or even the Liberals, but by the various nationalist or regionalist parties, particularly the Scottish Nationalist Party (SNP). The SNP holds 18 of the 71 Scottish seats at Westminster and chances are that they will increase this substantial share. The SNP stands for eventual self-government for Scotland, but its most immediate goal is economic independence.

The Scots--like the English--have been oversold on North Sea Oil and confidently expect it to solve all their problems. Certainly it will bring a measure of prosperity to a wilted economy. But oil production will not reach its full potential until 1980, and the Scots as well as the English will need help before then if things continue to deteriorate.