Is it nearly the end of the line for the part-privatisation of London's Tube? A year and a half after they were first chosen as the preferred bidders, the Metronet and Tube Lines consortiums were due to finalise their deals this month. But as passengers so often find, delays are occurring (see news). Metronet is in the worse position. It hasn't even started to raise the £2.6bn it needs, and its lead banks are refusing to hand over a penny without an indemnity against a fresh legal challenge by Ken Livingstone. If this happens – and the mayor is threatening to appeal a European ruling that the government hasn't breached state aid rules in pursuing the deal – the PPP will be delayed until 2006. And any form of public subsidy to keep it alive would prove Livingstone's case. It's hard to see how that impasse can be broken.

Tube Lines' prospects look superficially brighter. It might be in a position to take over the Jubilee, Northern and Piccadilly lines as early as next month. But can Amey still finance its £60m contribution? One rumour doing the rounds is that US engineer Bechtel, a fellow consortium member, may buy Amey – and we all know that firm's reputation as a troubleshooter.

The Tube deal hasn't quite hit the buffers. Something has to be done about the scandalous state of the network, and for all his bluster, Livingstone hasn't produced a viable alternative to the PPP. Nor has the government got the cash to fund it publicly. But the political momentum is with the mayor – the more delays he engineers, the more that public support for the PPP will ebb. He lost a big battle when he was defeated in the courts this summer; he may yet win the war.

After four years and two judicial reviews, one last attempt must be made to save the PPP – and not just for the sake of passengers. The survival of Amey and Atkins may depend on the outcome. The first task is to bring the bankers onside, but the Tube's fate lies with the politicians. It's Blair vs Livingstone. One hopes that Tony has gone too far to back down – but don't bet too heavily against a shock cancellation and meagre pay-offs for the wretched bidders. Remember Railtrack.

Death by insurance
The crisis of the spiralling insurance premiums continues (pages 26-28). As firms report ludicrous rises in employers' liability cover – one roofer's bill went from £7000 to £200,000 in two years – we are hearing warnings that many will go into receivership, bringing sites to a halt, or work without cover. Firms of all sizes are being hit, but small specialists are being punched silly. How is Ray Webber, on today's cover, to cope if his next bill is five times his annual profit? Hats off, then, to the roofers for their decision to follow the example of the big architects and explore the idea of a mutual fund, rather than bleating for government aid. Ministers can help by accelerating trials of single-project insurance, but construction's best hope is market forces. With insurers charging tiny scaffolders £100,000, it won't be long before someone else wants a slice of the action.