Tax bill passage pinned to big push by Reagan

Congressional leaders said the largest tax increase bill in US history is doomed unless President Reagan throws his full support behind it.

The warnings came as a conference committee of the House and Senate met on the politically volatile plan to raise $98.9 billion over three years. Noting widespread opposition among even House Republicans, House Speaker Thomas P. O'Neill said Mr. Reagan must deliver at least 100 votes to gain passage.