"We don't want to be a charity that bans things," said Sarah Lee, parliamentary manager at CRUK.
Cancer Research is one of several large charities, including the NSPCC and the RSPCA, to have been accused of developing a taste for banning things. Debate on the issue was sparked by an article in The Spectator magazine, which charged the sector with being "an author of intolerance".
Kevin Shinkwin, cancer campaigns manager at CRUK, said future campaigns would be "positive and evidence-based". But he refuted the suggestion that the smoke-free campaign was just about a ban.
He said: "It's about helping people to realise that, if at all possible, prevention is the ideal way forward."
However, the NSPCC, which continues to push for a ban on smacking, doesn't share CRUK's concerns.
"We make no apology for the strong messages of our campaigns," said John Grounds, director of communications at the NSPCC. "On average, every week in England and Wales, one child is killed at the hands of its parents. We do want hitting children banned, and we will keep campaigning until we achieve our goal."
A spokesman for the RSPCA, which played a central role in the campaign to ban foxhunting and which is now calling on the Government to ban the docking of dogs' tails, said: "We're not concerned. We don't believe we have a growing reputation for banning things."