Under the change, the independent Office of Congressional Ethics would come under the control of the House Ethics Committee.

Republican leaders in the House had opposed the change. The newly elected Congress meets later and the full House will vote on the proposed new rules.

Democrats reacted angrily to the vote.

It came on the eve of the start of a major power shift in Washington, with Republicans now holding all the levers of power for the first time in nine years.

The vote happened behind closed doors on a bank holiday, with no advance notice the issue was being considered.

But its supporters say it will enhance ethics supervision because the office had conducted witch-hunts against both parties.