Michael Conaway, the Texas Republican leading the bipartisan investigation, said the committee Republicans agreed with the conclusions of American intelligence agencies that Russia had interfered with the election, but they broke with the agencies on one crucial point that the Russians had favored Mr. Trump’s candidacy.

Conaway said the committee completed a 150-page draft report which includes more than 25 recommendations for Congress and the executive branch to improve election security. They include government response to cyber-attacks, campaign finance transparency, and counterintelligence practices related to political campaigns and unauthorized disclosures. The report is expected to be submitted to Democrats on Tuesday.