Paul Ryan says he will not support Donald Trump as open warfare breaks out among Republicans

Open warfare has broken out between Donald Trump and the senior leadership of the Republicans after the party’s most senior elected official said he would not campaign for the presidential nominee. Reports said he implied it was all but certain that the Democrats were poised to win the White House.

In a development that left political historians struggling to find a precedent, House Speaker Paul Ryan said that he would focus on helping members of the Congress get reelected rather than putting his efforts into helping the presidential candidate. He did, however, stop short of formally withdrawing his support for Mr Trump.

Mr Ryan made his comments during an emergency meeting of Republican politicians in Washington, where he said he would neither defend him or campaign with him. Mr Ryan told his members that “you all need to do what’s best for you in your district”, according to a report by Politico.

Mr Trump was quick to hit back on Twitter. “Paul Ryan should spend more time on balancing the budget, jobs and illegal immigration and not waste his time on fighting Republican nominee,” he said.

Mr Ryan's comments have sparked a furious backlash among Mr Trump's hardline supporters.

The Republicans’ Dana Rohrabacher of California said party members distancing themselves from Mr Trump were “cowards”.

Meanwhile the Representative for Arizona, Trent Franks, said the move would clear the way for Hillary Clinton to enter the White House, and referencing her stance on abortion, said it would end with foetuses being torn “limb from limb”.

The relationship between Mr Trump and Mr Ryan and other senior Republicans has never been anything but cold. The Republican establishment was desperate to nominate any candidate other than Mr Trump, who tore up Republican orthodoxies, vowed to shake up Washington and was not afraid to criticise Republican officials.

After Mr Trump became the de facto Republican candidate when all other candidate dropped out, Mr Ryan said he was still not ready to endorse the new York tycoon. He eventually did so by means of an op-ed article in his local paper.

Mr Trump has similarly not hidden his disdain for Mr Ryan and other senior elected Republicans. At various times during his campaign, he has asked that they be quiet if they are not prepared to help him.

Mr Ryan was one of many senior officials who denounced comments by Mr Trump that were published last week and in which boasted about sexually assaulting women. The comments were recorded in 2005 while filming a segment for Access Hollywood.

Mr Trump has grudgingly apologised for the comments. But he has also said they pale in comparison to the real sexual history of Bill Clinton, who over the years had been accused of sexual assault by a series of women. He said Ms Clinton was guilty of attacking many of those women who had claimed they had been assaulted.

Reuters said that in his conversation with fellow Republicans on Monday,

Mr Ryan said that he would spend the remainder of the election campaign making sure that if Ms Clinton wins in November, she does not get a “blank check” in the form of Democrat-controlled Congress. Republicans currently control both the House and Senate.

Republican members of Congress are worried that Mr Trump’s campaign could ruin their chances of holding their majorities in the elections and inflict long-term damage on the party.

Nearly half of all 332 incumbent Republican senators, congress members and governors have condemned Mr Trump's remarks, and roughly 1 in 10 have called on him to drop out of the race, according to a Reuters review of official statements and local news coverage.

But any attempt to replace Trump on the ballot this close to Election Day would face huge legal and logistical hurdles.

A defiant Mr Trump went on the offensive in a vicious presidential debate on Sunday, saying Ms Clinton would go to jail if he were president and attacking her husband, Mr Clinton, for his treatment of women.