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) 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 (5ft), while Spain, like the UK, has a 2m rule.
The US advises to keep 6ft (1.8m) 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.
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.