The cabinet is to meet later to discuss the further easing of the coronavirus lockdown as Boris Johnson continues to be engulfed by claims his senior aide Dominic Cummings breached the rules.

The prime minister is this week expected to set out details of plans to lift restrictions.

But some Tory backbench MPs say the row has undermined the government's message and want Mr Cummings to resign.

Mr Johnson has defended his aide, who had travelled from London to Durham.

Speaking at Sunday's Downing Street briefing, the prime minister said he believed Mr Cummings had "no alternative" but to make the journey at the end of March for childcare "when both he and his wife were about to be incapacitated by coronavirus".

At the press conference, Mr Johnson also confirmed the phased reopening of England's primary schools will begin on 1 June.

The plans to be outlined by the government will reportedly include information about the reopening of some non-essential shops in June.

However, BBC political correspondent Iain Watson said Mr Johnson is finding it difficult to shift the political focus away from his key adviser.

Those criticising the prime minister include scientists on key government committees.

Stephen Reicher, a professor of social psychology who has advised the government on behavioural science during the pandemic, said the prime minister's backing of Mr Cummings made him feel "dismay".

He said trust was vital to maintaining public health measures. "You can't have trust if people have a sense of them and us, that there's one rule for them and another rule for us," he told the BBC.

Two Church of England bishops have also criticised the prime minister.

The Bishop of Leeds, the Right Reverend Nick Baines, said Mr Johnson was treating people "as mugs" and the Bishop of Bristol, the Right Reverend Vivienne Faull, accused the prime minister of having "no respect for people".