Candidates bidding to replace Theresa May as Britain's prime minister and the leader of its ruling Conservative Party are vying to separate themselves from the pack in a crowded leadership race that had, as of Monday, attracted 13 competitors and much criticism.

Leadership battles typically attract a handful of hopefuls but this is the largest in Conservative Party history.

The BBC said on Monday the overcrowded race had led some senior members of the Conservative Party, including Housing Minister James Brokenshire, to urge fringe candidates to pull out in order to save time and leave the waters less muddied.

"We simply do not have the luxury of weeks of navel gazing or days and days of whittling candidates down to the final two," Brokenshire said in a speech at the Policy Exchange, a center-right think tank.

Elder statesman and former chancellor of the exchequer Ken Clarke said on BBC Radio 4's Today program that the contest had become a "shambles"and was "in danger of becoming a rather tragic farce, unless some order is brought into it".

Hopefuls have been seeking high-profile endorsements and unveiling policy proposals ahead of May's resignation on Friday.

Former foreign secretary Boris Johnson, who is seen by many as a frontrunner, got a thumbs-up from United States President Donald Trump on the weekend and was further boosted by Liz Truss, chief secretary to the Treasury, and Kwasi Kwarteng, the Brexit minister.

Michael Gove, the UK's environment secretary, has been endorsed by former education secretary Nicky Morgan, Cabinet minister Amber Rudd, and Mel Stride, leader of the House of Commons.

And Rory Stewart, the international development minister, has been endorsed by Justice Secretary David Gauke.

May is standing down because of widespread dissatisfaction within the party about how she has handled the UK's pending departure from the European Union. Candidates have unveiled their Brexit stances. Some favor an immediate hard Brexit, others favor reopening negotiations with the EU and a possible deferral of the scheduled Oct 31 departure date, and others are ranged in between.

Candidates have also unveiled other policy plans.

Johnson said in his column in the Daily Telegraph that he would like to increase per-student funding sent to secondary schools to a minimum of 5,000 pounds ($6,300) a year.

Matt Hancock, the health secretary, wants to establish an Irish Border Council to work with communities to avoid post-Brexi tdisruption along the border between the Republic of Ireland and Northern Ireland.

Home Secretary Sajid

Javid wants to spend 100 billion pounds on improving the UK's infrastructure.

And Sam Gyimah, the former universities minister, wants a second referendum on whether the UK should leave the EU.

Conservative Party grandees, meanwhile, have appealed to the party's 1922 Committee, which manages rules and discipline, and asked it to look at the rules surrounding leadership elections. Currently, MPs only need two other MPs to back them in order to stand in a leadership race. The 1922 Committee will look at whether prospective candidates should jump through more hoops in order to stand, something that would likely lead to smaller fields.

The committee is expected to make a decision on Tuesday.

The 13 hopefuls

James Cleverly

Michael Gove

Sam Gyimah

Matt Hancock

Mark Harper

Jeremy Hunt

SajidJavid

Boris Johnson

Andrea Leadsom

Kit Malthouse

Esther McVey

Dominic Raab

Rory Stewart