When workplaces around England and Wales become smoke-free zones in 2007, MPs and peers will be able to continue happily puffing on a cigar or cigarette at their desks.
Although smoking was recently banned in the Commons' corridors and restaurants, some of the eight bars in the Commons will be among the last bastions of public smoking in the United Kingdom, alongside private members' clubs.
An obscure historic loophole exempts the Palace of Westminster from health and safety laws.
MPs who favour a complete ban said yesterday that it was a farce for the lawmakers not to be covered by the new law outlawing smoking.
Kevin Barron, the Labour MP for Rother Valley, said Parliament should "get its own house in order".
"If they are passing the legislation it should operate in the Palace as well," he said.
Deborah Arnott, director of the anti-smoking lobby group Ash, said it was hypocritical.
"It is ludicrous and shows how ridiculous the new laws are going to be that it doesn't cover the Palace of Westminster. It is completely hypocritical of MPs not to ban smoking in the Palace of Westminster. It means workers there are not being protected, while other workers are."
The Commons authorities confirmed that the House would not be covered by the ban, although they said that smoking had recently been outlawed in many parts of the parliamentary estate, including the Tea Rooms, to protect public health.
"It [the Palace of Westminster] is not technically covered by the ban. That is right," said a parliamentary spokesman. "In bars where food is served smoking is banned but it is still allowed in all the bars that don't serve food except Strangers' bar where it is banned. It has been banned in all open spaces. No one can smoke in the committee corridor any more. MPs can smoke in their offices if they want to."
A spokesman for the Department of Health said that Parliament would not be forced to abide by the law, which will outlaw smoking in workplaces and in pubs and clubs that serve food. But smoking will be allowed in pubs that do not serve food so long as it is not close to the bar area. The Government is also keeping open the option of "sealed smoking rooms".
A spokesman for the Department of Health said: "It will be illegal to smoke in an office. In all workplaces it will be banned."
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