Boris Johnson has flown back from talks on the reunification of Cyprus to attend a parliamentary vote on the Queen’s Speech – the first test of the Conservatives’ control of the House of Commons since the General Election.

The Foreign Secretary left the summit in Switzerland before formal negotiations got under way on Wednesday with a vote looming on a Labour amendment to the Government’s legislative programme.

He held meetings with key players after an opening dinner on Tuesday evening and so scrapped plans to hold further discussions on Wednesday morning alongside Europe Minister Sir Alan Duncan.

Mr Johnson and Sir Alan’s departures as formal talks got under way appear to illustrate the precarious position of Theresa May’s minority Government, which is relying on the Democratic Unionist Party (DUP) to get its business through Parliament.

The Foreign Secretary was back in the UK in time to sit on the Government frontbench for Prime Minister’s Questions at noon.

Sir Alan is expected to return to the talks at the Crans-Montana ski resort on Friday, after further votes on the Queen’s Speech on Thursday, with the UK currently being represented by its special envoy on Cyprus, Jonathan Allen.

The Foreign Office (FCO) said all parties at the talks “understand” the ministers’ need to return home and stressed that Mr Johnson’s attendance showed how important the talks are to Britain.

During the visit he met with Greek Cypriot president Nicos Anastasiades, Turkish Cypriot leader Mustafa Akinci, United Nations special adviser on Cyprus Espen Barth Eide, and the foreign ministers of Greece and Turkey.

Britain, as the formal colonial power, is acting as a “guarantor” to the talks alongside Greece and Turkey, and it is believed the Government is optimistic about a breakthrough despite years of failed diplomatic initiatives.

Mr Johnson may return depending on the progress of the negotiations, due to last until July 7, amid hopes of a high-level agreement by next week.

The island has been divided since 1974 when Turkish troops staged an invasion in response to a coup by Greek Cypriots aimed at uniting with Greece.