A ban on smokers adopting children under the age of five has been criticised as "unfair and inflexible".
Portsmouth City Council has become the latest authority to impose the restriction recommended by the British Association for Adoption and Fostering.
But councillor Luke Stubbs said someone should not lose out on the chance to adopt just because they are a smoker.
He said: "Smokers are the only group who have a blanket prohibition on adopting young children."
The South Coast Adoption Consortium, which consists of the Isle of Wight, Poole, Southampton, West Sussex and Portsmouth, is following the guideline issued by the BAAF.
Councillor Eleanor Scott, of Portsmouth City Council, defended the tough stance.
She said: "Let's look at this from the perspective of a four-year-old girl - she's probably in local authority care because something has gone pretty horribly wrong in her little life already.
"She needs the best that we can do for her and I don't think it's reasonable for us to say 'tell you what you're four-years-old, you've had a tough life already, we're going to put you in a home where someone is smoking 60 a day'."
But Mr Stubbs, who is a non-smoker, believes the policy goes too far.
"Smoking is not a good thing, it is a health risk and should be a negative factor when you are considering someone for adoption," he said.
"But I do not think you should be ruled out completely just because you smoke."
"The policy should be more flexible and should consider people on a case-by-case basis."
He urged the council to reconsider its policy.
BAAF claims that 17,000 children under the age of five are admitted to hospital every year in the UK "with illnesses resulting from passive smoking".
The charity warns that a council risks potential legal problems if a child develops a smoke-related disorder after being placed with a carer who smokes.