Birmingham MP Lynne Jones has won a major victory in her campaign to ensure smoking is banned in all pubs and clubs.
The Prime Minister has agreed to allow Labour MPs a free vote when smoking is debated in the Commons - which means they can push through a complete ban.
Dr Jones (Lab Selly Oak) tabled a Commons motion demanding a free vote which was signed by 102 MPs.
Yesterday Downing Street announced Tony Blair had decided to allow backbenchers to vote as they wished when legislation is discussed over the next few weeks.
Ministers had previously planned a partial ban, which would allow smoking to continue in pubs which do not serve food.
By telling MPs they are free to vote as they wish, Mr Blair has made it likely the Commons will instead approve a total ban, as exists in Ireland.
Health Secretary Patricia Hewitt swiftly let it be known she would support the move to make all bars tobacco-free.
And Mr Blair's official spokesman said he now recognised the "momentum" of the public mood towards totally smoke-free zones.
Members of the Health Select Committee, including Worcestershire MP Richard Taylor (Ind Wyre Forest), have already tabled an amendment which would extend the ban to all licensed premises in England.
Dr Jones said: "I am delighted. It is the first time a very sensible idea I have put forward to the Government has actually been taken up by the Government. I hope that will continue."
She now expected the Commons to introduce a blanket smoking ban, she said.
"I think the majority of Labour MPs will vote for a complete ban, I would think most Lib Dems and many Tories will too."
The Prime Minister's official spokesman said: "After listen-ing to the range of opinions on the smoking issue, health Ministers intend to hold discussions with MPs seeking to amend the Bill to remove the exemption of non-food pubs.
"Following these discussions, it is the Government's intention to allow its MPs, including ministers, a free vote on the amendment.
"We recognise that the public debate has moved on. Also the debate within the entertainment industry has moved on and people have expressed concerns about the practicality of separating food and non-food areas and so on."
The Downing Street U-turn followed months of pressure to scrap proposals to exempt premises not serving food.