Boris Johnson accused of having 'no negotiating strategy' after reiterating Brexit demand to scrap backstop

Boris Johnson has been accused of having "no negotiating strategy" after repeating his Brexit demand for the Irish backstop to be scrapped in his first letter to Donald Tusk.

Just hours after one EU leader said the withdrawal agreement "cannot be reopened", the prime minister described the deal negotiated by Theresa May's government as "unviable".

Mr Johnson said the problems with the backstop – the bloc's insurance policy to prevent a hard border in Northern Ireland – "run much deeper than the simple political reality that it has three times been rejected" by the Commons.

In his four-page letter to the European Council president, he outlined his Brexit red lines, and said the backstop "cannot form part of an agreed withdrawal agreement".

"This is a fact we must both acknowledge," he wrote. "I believe the task before us is to strive to find other solutions, and I believe an agreement is possible."

Ahead of talks with Emmanuel Macron and Angela Merkel in Paris and Berlin later this week, he described the backstop as "anti-democratic" and "inconsistent" with the UK's plans for a future relationship with the EU.

But Sir Keir Starmer, the shadow Brexit secretary, said: "The letter confirms that [Mr] Johnson has no negotiating strategy. He suggests (unspecified) alternatives to the backstop. And if they don't work: further (unspecified) alternatives to the backstop. Why didn't anyone think of that before."

Mr Johnson wrote: "The backstop locks the UK, potentially indefinitely, into an international treaty which will bind us into a customs union and which applies large areas of single market legislation in Northern Ireland.