When Councillor Timothy J. Toomey announced he would run for a seat on Beacon Hill, he said he was looking forward to the campaign, despite the reputation and experience of his challenger--five-term Representative Peter A. Vellucci.

But barely one week later, Vellucci made a bombshell announcement that he would not seek re-election, leaving Toomey alone in the race for the Democratic nomination and general election.

Vellucci said in a statement released last Tuesday that he is not seeking a sixth term because he wants to spend more time with his family.

"When you have a business, a family, and a public office, something gets less attention," the statement said. "It is now time to reorder my priorities to give more time to my family."

Vellucci, the father of six and the grandfather of one, also said in the release that "one must keep things in perspective and know when to leave public office."

According to Karen L. Uminski, a legislative aide, Vellucci and his wife have been thinking about the decision for six months. She did add, however, that Vellucci had also entertained the idea of running for a state Senate position.

Vellucci aides and friends deny that his decision leave public office was spurred by Toomey's entrance into the race. But local political observers say the real reason Vellucci bowed out is because he "saw the writing on the wall."

"It's pretty clear that he [Vellucci] wasn't up for the fight," said Robert Winters, a Cambridge resident and political observer. "And I don't know how much of a fight it would have been."

Winters added that he thought Vellucci "saw there was no future" for his political career once Toomey announced his candidacy.

Toomey, who could not be reached for comment yesterday, shocked Cambridge politicos earlier this year when he placed an unexpected third in preliminary voting for the City Council. At the time many thought the one-term Independent councillor would face a tough challenge from Alfred E. Vellucci, the former mayor and the father of Peter Vellucci.

But Toomey easily bested Alfred Vellucci, who narrowly lost his bid for re-election. According to some Peter, Vellucci's successful career was based on the reputation of the Vellucci family name.

But other political observers said the younger Vellucci isn't the kind of politician to shy away from a fight. "If Peter was going to run away, he would have run away from the race with Marie Howe," said Clifford A. Truesdell '66, a seven-year Vellucci aide and campaign manager for the 1982 election.

In the 1982 election against Howe, the two candidates launched scathing personal attacks against each other in an election that would be remembered for negative campaigning.

Truesdell added that Toomey's entrance into the race was actually a "slight deterrent" to leaving office and that Vellucci was actually looking forward to the campaign.