Washington — Top Republican Senator Lindsey Graham of South Carolina, one of President Trump's key allies in Congress, proposed the GOP-controlled Senate change its rules to allow the president's impeachment trial to begin if House Speaker Nancy Pelosi does not send the articles of impeachment to the upper chamber this week.

Calling Pelosi's decision to withhold the two articles, passed by the House in a historic vote in December, a "political stunt," Graham told Fox News on Sunday that House Democrats are "trying to hold these articles over the head of the president."

"If we don't get the articles this week, then we need to take matters in our own hands and change the rules, deem them to be delivered to the Senate so we can start the trial, invite the House over to participate if they would like, if they don't come, dismiss the case and get on with governing the country," Graham said.

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The South Carolina Republican, who leads the Senate Judiciary Committee, said he wants Mr. Trump's impeachment trial to be over by the end of January and would move to change the Senate rules in "days not weeks" should Pelosi continue to hold on to the articles.

"We're not going to let Nancy Pelosi use the rules of the Senate to her advantage. This is dangerous for the presidency as an institution," Graham said. "They've impeached the president, but the speaker of the House is holding the articles back, trying to extort from the majority leader of the Senate a trial to her liking."

Pelosi has delayed the start of the impeachment trial by not transmitting the articles to the upper chamber. Lawmakers have been deadlocked over the parameters of the proceedings, with Democrats concerned with the fairness of the trial in the Senate.

Senate Minority Leader Chuck Schumer, a Democrat from New York, has called for four White House officials, including acting chief of staff Mick Mulvaney, to testify during the trial, but Majority Leader Mitch McConnell rejected the request.

On Friday, McConnell said the Senate cannot hold a trial without the articles of impeachment, as its "own rules don't provide for that." He accused Democrats of getting "cold feet" with impeachment. Schumer, meanwhile, said that if witnesses are not allowed to be called during Trump's trial, it will be nothing more than a "nationally televised meeting of the mock trial club."

Pelosi has not indicated when she may transmit the two articles, which charge the president with abuse of power and obstruction of Congress. The House must also first pass a resolution designating impeachment managers, House members who will serve as prosecutors in the trial.

During the impeachment trial of President Bill Clinton, Graham, then in the House, was one of 13 Republicans who served as an impeachment manager.