Germany and France have called for a Europe-wide deal on migration and asylum with the UK government, to capitalise on Labour’s more “constructive” approach to EU-UK relations.

In a letter to the EU home affairs commissioner, the German interior minister, Nancy Faeser, and her former French counterpart, Gérald Darmanin, said Brexit had gravely affected “the coherence of migration policies”.

“The absence of provisions governing the flow of people between the UK and the Schengen area,” they wrote, was “clearly contributing to the dynamics of irregular flows and to the danger posed to people using this route in the Channel and the North Sea.”

Darmanin and Faeser urged the European Commission to “rapidly” present “a draft negotiating mandate” for talks with the UK on asylum and migration.

“The arrival in office of a new British government, demonstrating its intention to cooperate constructively with the EU, seems to us to be conducive to concrete progress on this issue,” stated the letter, first reported by AFP.

France has long sought an EU-wide asylum pact with the UK, but Germany has never signalled such strong support until now. Darmanin, who was replaced last week during the French government reshuffle, called for a migration treaty between the EU and UK in 2021 but failed to win support from other member states.

The politics of an EU-UK migration deal could prove sensitive for Starmer’s government, which has been accused by refugee charities of adopting the Conservatives’ harsh language and policies on asylum and migration. France has wanted British officials to process asylum claims in the areas around French ports, a position rejected by previous Conservative governments, who feared this would encourage more people to seek entry to the UK.

The absence of legal routes to the UK “feeds smuggling networks”, the letter states.

This month alone, at least 20 people have died attempting to cross the Channel in two separate incidents. British officials estimate that more than 22,000 refugees and migrants have arrived in England via irregular Channel crossings so far this year.

The European Commission, which has previously rebuffed proposals to negotiate an EU-UK agreement, declined to comment on the letter. Under the last Conservative government, when EU-UK relations were at a low point during tensions over the Northern Ireland protocol, the EU home affairs commissioner, Ylva Johansson, signalled that a migration deal with the UK was not a priority, citing “limited appetite” from EU member states.

Asked to comment on whether the commission had moved on from Johansson’s previous comments, a commission spokesperson said: “Our positions on [EU-UK] relations are indeed well known,” without elaborating further.

Despite the support of the EU’s biggest member states, the prospects of an EU-UK deal on migration any time soon appear slim. The EU executive is preoccupied with the transition to a new team of commissioners, who are not expected to take office until 1 December.

An EU-UK summit is pencilled in for next spring, after the changeover of leadership at the EU’s main institutions.

The spokesperson said the “commission is fully working” and would issue a reply to the letter “in due course to the appropriate authorities”.