In a U-turn by No 10, the Prime Minister's official spokesman for the first time signalled that Mr Livingstone's Bill on fox-hunting was doomed to failure in this session of Parliament through lack of time - in spite of repeated government promises of support for legislation.
The spokesman denied it had anything to do with Tony Blair's opposition to Mr Livingstone standing against Frank Dobson as Labour's candidate for the mayor of London, but few MPs were in any doubt that Downing Street was keen to avoid Mr Livingstone being given a golden publicity platform with his Bill.
Mr Dobson angrily protested to Millbank that the Bill "could make the difference between winning and losing" the Labour race to be the mayoral candidate. But No 10 said the Bill would get no government time until after the Burns inquiry into fox-hunting, which is not due to end until 21 June - too late for a Bill in this session to reach the statute book. Mr Blair's official spokesman confirmed this meant that the Government would be looking to a Bill in the next session of Parliament, to be introduced by another MP, to deliver a ban on fox-hunting. But with Mr Blair expected to go to the country inspring 2001, it will not become law before an early general election.
The fact that Mr Livingstone has chosen to take up the Bill also came as a relief to business managers who feared that the controversial fox- hunting legislation would block government legislation in the House of Lords, where it was almost certain to be defeated by backwoods Tories, crossbenchers and some Labour peers.
Mr Dobson, who will be backed by Mo Mowlam in a tour of Dulwich, south- east London, today said: "Fox-hunting should be banned. I will support any measure to bring that about. I know that most Londoners support my view that there are far more important issues - jobs, crime and transport."
A source inside the Dobson camp said: "Livingstone is number eight and everyone knows that he won't get a second reading for his Bill. If fox- hunting is going to be banned, it will be through the time that Downing Street gives after the Burns inquiry."
The hardening of Downing Street's attitude against early legislation will come as a relief to the Countryside Alliance, which was braced for a fresh battle over banning fox-hunting, which it claims would cost 16,000 jobs in rural areas.
Accusing Mr Livingstone of a "cynical electioneering move", the Countryside Alliance's chief executive, Richard Burge, said: "His Bill deserves to fail and we expect to kill it. In the meantime, we and other organisations will be making our case to the forthcoming [Burns] hunting inquiry."
Mr Livingstone, who has a back-garden haven for newts and frogs, said he was not a sentimentalist about foxes.
"What this Bill is about is ending cruelty, not creating some sort of heaven. That is not the way nature works and earlier this spring a fox came hunting in my garden and bit the head off a tortoise. So I have no illusions - foxes can be wicked old things. That is nature."
He said foxes could be controlled by shooting and the Bill was intended to end cruelty by humans to animals.