By David Lawder WASHINGTON (Reuters) - House of Representatives Republican leaders on Wednesday predicted passage of a budget blueprint offered by Representative Paul Ryan, despite criticism from conservative Tea Party activists who said the plan would not eliminate federal deficits quickly enough. "It'll pass," said Republican Representative Kevin McCarthy, the No. 3 Republican in the House who, as Majority Whip, is responsible for rounding up votes for legislation. The Ryan plan, which proposes deep cuts to healthcare, social safety net and other domestic programs in order to reach a small surplus by 2024 while boosting defense spending, could face resistance from the most conservative Republicans in the House. That's the most I can say right now," said Representative Justin Amash, a libertarian Republican from Michigan, when asked if he would support the plan from Ryan, who chairs the House Budget Committee.