The United Kingdom prime minister's support of his chief advisor, who has been accused of breaking the country's lockdown rules, may have undermined the nation's fight against the novel coronavirus, politicians and commentators have claimed.

Critics, including around 20 elected legislators from Boris Johnson's ruling Conservative Party, slammed the national leader for backing Dominic Cummings, an unelected aide, after it was revealed on the weekend that he drove from London to the UK's Northeast at the height of the lockdown so he could stay in a cottage on his parents' farm, an excursion that appeared to break several lockdown rules.

The journey, and Johnson's subsequent refusal to criticize either it or an alleged second such trip, may damage the lockdown, the critics said, because it sets a poor example of how to behave amid largely unenforced and unenforceable lockdown rules.

The Labour Party called for a public inquiry, while Nicola Sturgeon, the first minister of Scotland, said Cummings' conduct could have "serious" consequences.

David Warburton, a Conservative Party member of Parliament, said on BBC Breakfast that Cummings had damaged "the government and the country that he's supposed to be serving".

And Ed Davey, the acting leader of the Liberal Democrats, said: "The instruction the prime minister gave us all to stay at home has been breached by his top adviser and that's what you can't get away from."

Shadow health secretary Jonathan Ashworth added: "The hypocrisy stinks and people know it."

Johnson said on the weekend that Cummings had made the 420-kilometer journey because he realized "both he and his wife were about to be incapacitated by coronavirus" and that they needed a childminder.

Cummings insisted at a news briefing on Monday afternoon that he had complied with the letter of the law because his 4-year-old child could be thought of as a vulnerable person, opening the door to him taking action outside the lockdown rules.

And he added that he did not ask the prime minister at the time whether the trip was appropriate because "he was ill himself and he had huge problems to deal with".

A defiant Cummings said he did not regret his decision to travel halfway across the country at a time when the government was urging people to stay at home in order to protect the National Health Service.

Earlier on Monday, Chancellor of the Exchequer Rishi Sunak authorized the potential bailout of strategically important companies that have been ruined by the pandemic.

Project Birch allows the nation to "inject state equity into companies drowning in debt", the Financial Times reported.

It said the Treasury hopes to help enterprises that have an important role in the nation's economy in sectors including aviation, aerospace, and steel production.

"In exceptional circumstances, where a viable company has exhausted all options and its failure would disproportionately harm the economy, we may consider support on a 'last resort' basis," a Treasury spokesperson told the FT.

The Financial Times also reported on Monday that the government is urging companies not to launch damaging lawsuits in attempts to resolve virus-related contractual disputes, but to seek solutions through mediation.

Government departments are concerned the pandemic has triggered a flood of lawsuits that could overwhelm the civil courts.

The new guidance from the Cabinet Office says: "Responsible and fair behavior is strongly encouraged in performing and enforcing contracts where there has been a material impact from COVID-19."

Meanwhile, the government told elite athletes they can now return to contact training, if they and their sporting associations feel it is safe.

The government says, initially, athletes should train in clusters of two or three before embarking on full-team training sessions.

The change follows soccer teams from the English Premier League resuming non-contact training on May 19.

Nigel Huddleston, from the UK's Department for Digital, Culture, Media and Sport, said: "This new guidance marks the latest phase of a carefully phased return to the training process for elite athletes, designed to limit the risk of injury and protect the health and safety of all involved."

He said athletes should not, however, share equipment.

Elsewhere in Europe, several nations further eased their lockdowns on Monday as both rates of infections and death tolls continued to improve.

Swimmers and fitness fans in Italy rejoiced after authorities in Rome reopened gyms and pools in all parts of the nation other than the hardest-hit region of Lombardy.

And, in Spain, the cities of Madrid and Barcelona finally joined the rest of the country in phase 1 of the three-phase easing of the national lockdown, meaning people can now gather in small groups and be served in the outdoor areas of bars and restaurants.

Greece, meanwhile, has reinstated ferry services to all of its islands and ports ahead of the full resumption of domestic tourism. The nation also allowed the reopening of cafes and restaurants on Monday, a move that was duplicated by the Czech Republic.