The prime minister was accused of being out of touch by flying abroad while the UK faces mounting problems with energy costs and labour shortages.
Boris Johnson is reportedly staying in a private villa in Marbella with his wife Carrie and their son Wilf.
Liberal Democrat leader Ed Davey, who is in Orkney, heavily criticised his opponent for leaving the country “at the height of this crisis”.
Mr Davey, a former energy minister in the Conservative-Lib Dem UK Government, said the prime minister should be overseeing talks for extra support in the troubled energy sector.
He said he’s “angry” at a “failure” to prepare for difficulties with industry, HGV drivers shortages and energy.
‘Quite shocking really’
“Then to go on holiday at the height of this crisis is quite shocking really,” Mr Davey said.
“It’s almost as if he doesn’t think there’s a crisis.
“I think we have a Conservative prime minister who is out of touch.
“I think people struggling with heating bills, struggling with high energy costs and shortages of labour are going to say this prime minister is totally incompetent.”
His mother passed away very sadly two or three weeks ago and he may have decided to take a short break.
– Business Secretary Kwasi Kwarteng defends Mr Johnson.
He was photographed at a holiday cottage on the coast with a bell tent pitched in a field near Applecross.
The prime minister’s foreign holiday was defended at the weekend.
UK Business Secretary Kwasi Kwarteng insisted it was “reasonable” and said he remains in “regular WhatsApp contact” with the Prime Minister.
Mr Kwarteng said: “He’s also had a year-and-a-half in which he’s almost lost his life to Covid, his mother passed away very sadly two or three weeks ago and he may have decided to take a short break.
“I think that’s something reasonable.”
Labour called for “urgent answers on who exactly is running the show”.