Republicans and Democrats, union leaders and the president of the Boston Chamber of Commerce, will speak from the same platform here when American Defense, Harvard Group holds a mass National Unity Meeting in the New Lecture Hall at 8o'clock Wednesday night.

The meeting will be similar to gatherings conducted throughout the country by the Council for Democracy to eliminate bitterness caused by the presidential campaign and to create national solidarity behind the defense drive.

Union Leaders Speak

The Democrats who are scheduled to speak are Congressman Joseph E. Casey of Massachusetts; Joseph Salerno, secretary of the C.I.O. affilated Amalgamated Clothing Workers' Union, Boston; and Kenneth I. Taylor, state secretary of the American Federation of Labor.

Representing anti-New Deal sentiment will be Oscar W. Haussermann '12, Boston lawyer and president of the Boston Chamber of Commerce; Professor O. M. W. Sprague '94, of the Harvard Business School, economic advisor to the Bank of England until 1932 and financial authority to the Secretary of the Treasury until he broke with President Roosevelt on his fiscal policies; and Colonel T. Gallup, acting judge advocate of Massachusetts, legal adviser to Governor Leverett Saltonstall on military service, who was elected to the General Court from this district on Tuesday.

Lewis Perry, principal of Philips Exeter Academy, will preside at the meeting.