Independent auditors are refusing to approve the Conservative Party's accounts.

PricewaterhouseCoopers told Tory officials that there is not enough income to guarantee the party's viability.

"It is worrying. The auditors have raised with us the fear that we are no longer a going concern because spending outstrips income. We struggled last year, but this year it is much worse," said a senior Tory source.

"The accounts were signed off last time because we had commitments of loans from benefactors, but they are not forthcoming."