Tough new election laws drawn up in response to Birmingham's postal voting scandal will encourage fringe parties such as the BNP, Conservatives will claim.
Tories are to attack provisions buried in the Government's Electoral Administration Bill, which has its Second Reading in the Commons this afternoon, to lower the threshold for losing deposits in Parliamentary elections.
This will give a boost to smaller parties, including the BNP, by allowing them to keep their £500 deposits if they gain just two per cent of the vote. They need five per cent.
According to the Conservatives, this will allow the BNP to stand candidates in more seats across the country - entitling them to party political broadcasts, and to Freepost mailings of their election literature.
The BNP lost their deposit in 11 Midland seats in the last election, costing £5,500.
But if the new laws but had been in place, they would have saved their deposit in every one of them, because they gained more than two per cent of the vote.
The affected constituencies are Birmingham Erdington, Dudley South, Birmingham Northfield, Aldridge-Brownhills, North Warwickshire, Burton in Staffordshire, Coventry North West, Newcastle-under-Lyme in Staffordshire, Solihull, Wolverhampton South West and Worcester.
And across the country, the BNP would have saved £36,500 in lost deposits.
The party is already strong in some Midland constituencies. In West Bromwich West they got 9.9 per cent of the vote at the last election.
The Bill has been bought in as a response to the voting scandal in Birmingham's council elections last year, which led to the poll for six city council seats being re-run.
It creates a specific offence of fraudulently applying for a postal vote, for the first time.
However, it is designed to increase participation as well as stamp out fraud, and introduces a series of measures such as lowering the minimum age of candidates to 16.
A spokeswoman for the Department for Constitutional Affairs said: "The aim of the clause was to broaden democracy by increasing the variety of people and parties that could stand at election.
"The clause was not aimed at encouraging the BNP. No matter how unpalatable people might find their politics, as long as they remain a legally registered party they will be covered by the same laws as everyone else."
Oliver Heald MP, Shadow Secretary of State for Constitutional Affairs, said: "At a time when there is growing concern about the rise of extremist parties, it beggars belief that the Labour Party wants to lower the hurdles for the far-left and far-right to receive freepost mailings and election broadcasts in Parliamentary elections."