Boris Johnson has refused to condemn his father for flying to Greece in apparent breach of Foreign Office guidance to avoid non-essential travel.

Stanley Johnson was widely criticised after reportedly travelling via Bulgaria – in order to avoid the ban on direct flights from the UK – to visit his Greek villa.

However during an LBC radio phone-in, the Prime Minister repeatedly refused to say whether he was “disappointed” with his father’s actions.

“I think you really ought to raise that with him. I am not going to get into details of family conversations,” he said.

“I think the overwhelming majority of the British people have understood what needs to be done and have been very prudent and that is the right thing to do.”

Mr Johnson again declined to criticise his father when asked at a Downing Street press briefing why the public should obey all the rules when his father and top aide Dominic Cummings had not done so.

He said: “Durham Police made it clear they were not pursuing that.

“I make it a normal practice not to comment on the movements and doings of my family.

“When you look at what the British public have done over the last three months, it has been a phenomenal effort to follow the guidance and get this thing under control.

“People have worked together and done an absolutely heroic job. We have got to keep that going now.”

Earlier this week, Mr Johnson senior posted a picture on social media of himself apparently arriving at Athens airport wearing a face mask.

The 79-year-old told the Daily Mail that he was visiting on “essential business” because he needed to “Covid-proof my property” ahead of the letting season.

His actions drew comparisons with the notorious visit by the Prime Minister’s top adviser Dominic Cummings to Barnard Castle during the height of lockdown, supposedly to test his eyesight after recovering from Covid-19.

My message is that the Government really is very much on people's side

Boris Johnson said he understood the anger that had been caused by that visit but insisted the Government was “very much on people’s side”.

“I really, really do understand people’s feelings about that. Most people in this country have shown huge forbearance and sacrifice – the overwhelming majority,” he said.

“My message is that the Government really is very much on people’s side.”

Earlier, Transport Secretary Grant Shapps disclosed that Greece was not on the initial list of countries from which travellers to England would no longer be required to quarantine for 14 days on arrival.

Mr Shapps said a decision on whether to add Greece to the list would have to wait until at least July 15 when the government in Athens will decide whether to lift its restrictions on travellers from the UK.

He said that if Mr Johnson senior returned to the UK before that date he would have to self-isolate for a fortnight “which he will be happy to do”.

Asked whether is visit to his villa constituted “essential business”, Mr Shapps said it was “up to an individual to decide”.

“There is certainly no law against it. This is travel advice,” he told the BBC Radio 4 Today programme.

“But what isn’t up to an individual to decide is when they return from that location then they will need to self-isolate, they will need to do that quarantine for 14 days.”