Unclear whether UK lawmakers have numbers to trigger PM May confidence vote- editors say

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LONDON, July 9 (Reuters) - It was unclear on Monday whether British lawmakers in Prime Minister Theresa May's Conservative Party had the numbers to trigger a confidence vote, political editors said on Monday.

A leadership challenge can be triggered if 15 percent of members of parliament in May's Conservative Party write a letter to the chairman of the party's so-called "1922 committee".

The Conservatives currently have 316 members of parliament (MPs (BSE: MPSLTD.BO - news) ) so 48 would need to write such letters to challenge May.

The 1922 committee is meeting on Monday to discuss May's plan to retain close ties with the EU after Brexit, a move that prompted the resignation of two of her most senior members of cabinet in the last 24 hours.

"Whispers Tory MPs have reached the magic number of the 48 letters required to force a confidence vote - no way of knowing yet if true - meeting at 1730," BBC political editor Laura Kuenssberg said on Twitter (Frankfurt: A1W6XZ - news) .

Tom Newton Dunn, the political editor of The Sun tabloid, said he had been told by someone close to the head of the 1922 Committee to treat the rumours with extreme caution: "In other words, not yet," he said on Twitter.

Robert Peston, political editor of broadcaster ITV (Frankfurt: A0BLQP - news) , said he did not expect any announcement of a confidence vote on Monday night. (Reporting by Guy Faulconbridge; writing by Kate Holton; editing by Michael Holden)