Party leaders hope to get the deficit down to pounds 3.5m by the end of the year, but they are seeking a change in the law to avoid running into the red during the next election campaign.
Tony Blair has given a clear signal that Labour could seek a cap on spending by the main parties for the next general election, as reported last week in The Independent.
The Prime Minister said in his keynote address that Labour would ask the Nolan Committee on standards in public life to look at party funding, and to come up with recommendations for changes in the law. "At the next election, all political parties will at last compete on a level playing field."
Ms Prosser said that, with "belt-tightening and good husbandry", the overdraft in the general fund would be kept down to pounds 3.5m by the end of the year, and there would be a "small, declining" overdraft in the general election fund. She promised that the pace of fund-raising would not diminish.
"The party cannot achieve its political objectives in one term. My job is to chivvy everyone along and make sure the next election war-chest builds up."
Defending the amount Labour spent on the election, Ms Prosser said the pounds 23m spent between 1993 and 1 May this year had produced a "powerful, imaginative and high- powered campaign".
She added: "It was at the same time ... focused and reached all corners of the UK and all levels of society."Reuse content