Analysis By Nick Assinder Political correspondent, BBC News website

The sight of one of Britain's greatest manufacturing plants collapsing with thousands of job losses is about the last image Labour would want to take into a general election campaign.

It is particularly dangerous for Tony Blair and Gordon Brown who have put the economy at the centre of their campaign.

Their boasts about the low unemployment and economic stability their government has embedded may well ring hollow in the ears of those affected by the closure.

Economic stability is at the heart of Labour's election campaign

So it is no wonder the prime minister made a 25 minute phone call to bosses at Shanghai Automotive in a last-minute attempt to rescue the deal with Rover.

But with that deal now apparently dead, and with New Labour, unlike its predecessors, set against state rescue packages, there is probably little the prime minister can do to now stop what looks like the inevitable.

And the fact that the closure and subsequent massive job losses will come in an area full of marginal Labour seats will only sharpen the dilemma for Mr Blair and the Labour party.

The Midlands has always been a volatile voting area and has previously returned Tory MPs - notably during Margaret Thatcher's heyday.

There are as many as 15 vulnerable seats which could be affected by the closure, with Birmingham Northfield and Yardley - where former minister Estelle Morris is standing down - in the firing line.

The plight of the workers at the Longbridge plant will be thrown into the election campaign.

Others could include Bromsgrove, Dudley South, Hall Green, Coventry South, Redditch and Stourbridge.

There are more than 6,000 Rover jobs immediately under threat but between 15,000 and 20,000 in support industries are also at risk.

That would have a devastating impact on the local area which has previously suffered from the closure of massive car plants.

Rescue package

It is not merely the job losses, it is the knock-on effects for the local communities that can prove so deeply scarring.

The social effects of such a closure in areas that have been relatively prosperous can be devastating and bring serious local problems.

The Midlands has seen its fair share of this in the past with the demise of the car industry going back to the 1970s.

Workers in 15 constituencies could be hit by Rover closures

The political symbolism could not be more graphic and it is certain the plight of the workers at the Longbridge plant will be thrown into the election campaign.

The opposition parties may not have been able to offer anything significantly different from the government, although questions have already been asked about the speed with which Trade Secretary Patricia Hewitt announced that administrators had been called in.

There will also be concerns over whether the government could have offered more security to the Chinese company to secure the deal.

Voter turnout

And, inevitably, there will be demands for a state rescue package, although the government's hands are tied from offering anything other than a bridging loan to such firms.

For the moment, at least, the best ministers can offer is a �40m aid package to help supply industries hit by the closure find alternative work.

But the electoral effect on a government that has made so much of its economic record and, in particular, stability, is difficult to predict.

The question the government is facing is whether Labour-supporting Midlands voters will feel disillusioned enough to turn to other parties.