An EU foreign affairs chief has mocked France for using a row over fishing rights to block the UK involvement in a continental security deal. Kaja Kallas, the former prime minister of Estonia, told of her shock at the impasse over Britain joining a £125 billion  (150bn euro) joint defence fund. 

She said she was “surprised how important fish are, considering the security situation”. Ms Kallas added: “'I'm definitely pushing this from my side because I think the UK is a very important defence and security partner, it's the most logical defence and security partner that we have and it is a beneficial relationship for both sides.”

While laughing, she continued: “I'm learning in this job … fish to the French they are very important.”

The UK has attempted to be included in the initiative in light of its leadership over the “coalition of the willing” aimed at bolstering the continent’s defence capabilities.

Although talks on the UK joining the initiative is underway, it has hit a roadblock because of wider demands on a EU-UK pact over fishing rights and migration.

Many EU member states want guarantees they will continue to have the same level of access to UK fishing waters as under a current deal that expires in June next year.

There is also a push for Sir Keir to cave in on a youth mobility scheme to give young Europeans greater freedom to come to the UK to study and work - and vice versa for young Britons.

It comes as the UK’s Defence Secretary John Healey urged Ukraine’s allies to “look hard” at what more they can do to help Kyiv as the UK announced a £450 million “surge” in military support on Friday.

He opened a meeting of the Ukraine Defence Contact Group (UDCG) in Brussels with a plea to his fellow defence ministers to “step up our support for Ukraine in the fight”.

He said: “Our job as defence ministers is to get urgent military aid into the hands of Ukrainian warfighters.

“And to those nations not making fresh commitments today, I urge you to look again, to look hard at what more you can do.

“All military aid now will help Ukraine in the fight today and help secure a durable peace tomorrow, because the Ukrainian armed forces must be their own strongest deterrent against further Russian attacks.”