Senior Conservative MPs are urging Boris Johnson to consider changing the 2m social distancing rule to 1.5m, amid fears for the hospitality sector.
Greg Clark, chair of the Commons science committee, told the Daily Telegraph it could "be the difference between people being able to go to work and losing their jobs".
Former Chancellor Lord Lamont said measures which could "compensate", such as face masks, should be considered.
Other countries have different rules.
While some lockdown measures are being eased across the UK, the social distancing rules, which say people from different households should stay 2m (6ft 6ins) apart from each other, still apply.
However, former business secretary Mr Clark wrote to the prime minister asking for Sage (Scientific Advisory Group for Emergencies) to review the rule.
Even if Sage did not recommend reducing the distance, it would be important for it to "clarify the rationale" behind 2m and explain "why the guidance in the UK differs from so many international comparators," Mr Clark said.
France and Italy say people should keep 1m (3ft) apart, as does the World Health Organization. Germany recommends a distance of 1.5m (4ft 11ins), while Spain, like the UK, has a 2m rule.
The US advises to keep 6ft apart.
On Thursday, England's chief medical officer Professor Chris Whitty reiterated that it was "really important" that people stayed 2m away from each other.
Speaking to BBC Radio 4's Today programme, Lord Lamont called on the advice to be re-examined, saying social distancing was causing "huge problems" for the hospitality sector.
"If you want a single measure that could help the hospitality sector, it would be a reduction in the social distancing from 2m to 1m," the Tory peer said, but insisted he would not want the government to "ignore" scientific and medical advice.
His comments come days after Kate Nicholls, chief executive of UK Hospitality, called for the distance to be reduced even further, to 1m (3ft 4ins).
She said: "If you have 2m social distancing that's the difference between opening at 30% of normal revenues or 60% with 1m social distancing."
What does the science say about the 2m rule?
A simple guide is that the closer you are to someone who is infected, the greater the risk.
Also the longer a person spends in close proximity with an infected person, the more the chance of catching the virus increases.
Sage reported that being exposed for six seconds at 1m is comparable to a one-minute exposure at 2m.
In its latest paper on the issue, from April, it recommends keeping the rule, saying 2m is a "good measure" of the distance where the direct person-to-person transmission risk drops significantly.
But it says it should be seen as a ballpark guide to distancing rather than an absolute value.
Read more on the science behind the 2m rule here.
Former Brexit Secretary David Davis said changes to the government's furlough scheme should be implemented "in-step" with a relaxation of the 2m rule.
The government is currently paying 80% of the salaries of 8.4 million UK workers - up to £2,500 a month - but from August, employers will have to start sharing the cost.
However Mr Davis said some firms would be unfairly disadvantaged if they had to shut because they could not social distance, while being forced to start paying towards staff costs again.
Speaking on Thursday, Mr Johnson said: "I must stress that to control the virus, everyone needs to stay alert, act responsibly, strictly observe social distancing rules, and stay 2m apart from those who you do not live with."