The Government has insisted Dominic Cummings was within the rules when he travelled 260 miles from London to his family home in Durham during the lockdown.

Mr Cummings said he wanted help from his family caring for his young son if he and his wife became too ill to do so alone.

Michael Gove tweeted: “Caring for your wife and child is not a crime.”

But when Boris Johnson introduced the UK lockdown he gave “a very simple instruction – you must stay at home”.

The Government’s guidance on circumstances in which a person may leave their home stated:

– For work, where you cannot work at home.

– Going to shops that are permitted to be open – to get things like food and medicine.

– To exercise or spend time outdoors.

– Any medical need, including to donate blood, avoid illness or injury, escape risk of harm, or to provide care or help to a vulnerable person.

No mention was made of childcare in the Government’s published guidance.

Provision is made in the Health Protection Act 2020 for key workers to access childcare or education services.

Under the heading “reasonable excuse” for leaving home, it states: “Childcare or educational facilities (where these are still available to a child in relation to whom that person is the parent, or has parental responsibility for, or care of the child).”

Mr Johnson said people should not meet family members who do not live with them.

The rule on meeting family was unequivocal.

It stated: “You should not be visiting family members who do not live in your home.

“You should keep in touch with them using phone or video calls.”

It did not say family could look after children if parents were unable to do so.

It was also clear on travel to holiday homes or caravans, people were not permitted to stay overnight anywhere other than their main home.

“Leaving your home – the place you live – to stay at another home is not allowed,” it said.

Only in exceptional circumstances were people allowed to attend relatives’ addresses; for example, to drop off food or medicine to their door.

However, Dr Jenny Harries said at the daily Downing Street press briefing on March 24 that a small child could be considered “vulnerable”.

“Clearly if you have adults who are unable to look after a small child, that is an exceptional circumstance,” she said.

“And if the individuals do not have access to care support – formal care support – or to family, they will be able to work through their local authority hubs.”

Even now the lockdown rules have been relaxed slightly, visiting friends or family in their own homes is still off limits.

The current guidance states: “As with before, you cannot visit friends and family in their homes.”

The Government guidance also said: “We are advising those who are at increased risk of severe illness from coronavirus (Covid-19) to be particularly stringent in following social distancing measures.

“This group includes those who are aged 70 or older (regardless of medical conditions).”

It added: “If you are showing coronavirus symptoms, or if you or any of your household are self-isolating, you should stay at home – this is critical to staying safe and saving lives.”

Downing Street previously confirmed that Mr Cummings had started displaying coronavirus symptoms “over the weekend” of March 28 and 29.

The Government’s guidance on self-isolation stated: “If you live with others and you are the first in the household to have symptoms of coronavirus (Covid-19), then you must stay at home for at least seven days, but all other household members who remain well must stay at home and not leave the house for 14 days.

“The 14-day period starts from the day when the first person in the house became ill.”

In a statement on Saturday, Number 10 acknowledged Mr Cummings’ wife Mary Wakefield had symptoms of coronavirus when the family decided to travel.

“Owing to his wife being infected with suspected coronavirus and the high likelihood that he would himself become unwell, it was essential for Dominic Cummings to ensure his young child could be properly cared for,” a spokesman said.