Mark Pritchard, MP for The Wrekin, said it would also be necessary to consider the safety of non-smokers if it was decided that outside areas at pubs, restaurants and cafes could reopen.
The Prime Minister is expected to announce his 'road map' for relaxing some of the restrictions on Sunday, and Health Secretary Matt Hancock has hinted that outdoor seating at cafes could reopen.
But Mr Pritchard said new rules would need to be introduced if that was the case.
"If cafes, restaurants & pubs with outside areas open next week then new rules on smoking in external public areas should be introduced by the Ministry of Housing, Communities and Local Government," he said.
"Outside seating should not be dominated by smokers exposing customers to secondary smoke."