Outgoing Prime Minister Boris Johnson drew fresh criticism Monday over his handling of multiple crises afflicting Britain, after taking a second summer holiday just weeks before he leaves office.

The main opposition Labour party accused Johnson, who is due to leave office on September 6, of having "one big party" as many Britons struggle with a surging cost-of-living crisis.

With inflation at its highest rate in decades and the UK predicted to slump into recession, people across England are also struggling with the impact of a drought officially declared on Friday.

But Johnson, who only returned to his Downing Street desk last week after enjoying a five-day belated honeymoon with wife Carrie in Slovenia, opted to take another break this week in Greece.

A Greek website posted footage of the British leader shopping at a supermarket in a coastal town near Athens, stocking up on items including food and wine.

"It's all just one big party for Boris Johnson while the country struggles to pay their bills," a spokesman for Labour said.

Confirming Johnson was on holiday this week, his spokesman told reporters he would "obviously be kept informed on any urgent issues and make decisions particularly those (related to) national security for example".

He noted deputy prime minister Dominic Raab could deputise for Johnson in any meetings, "but as far as I'm aware there are no such meetings currently scheduled".

Johnson will soon have a lot more free time after he hands power over to either Liz Truss or Rishi Sunak as the next Conservative leader in three weeks.

He was forced to announce his departure from office earlier this summer following dozens of resignations from his government over a slew of scandals.

Truss is currently the favourite to win a summer-long leadership contest set to be decided by approximately 200,000 Conservative party members.

The result will be announced on September 5, with the victor to replace Johnson the following day.