British finance minister George Osborne said he will cut a tax on nearly all property purchases from midnight, removing a long-standing grievance of home buyers five months before an election.

Presenting his half-yearly update on the country's finances on Wednesday, Osborne said the Stamp Duty tax would be lowered for the majority of home buyers while those buying houses at the top end of the market would have to pay more.

The increase for the most wealthy could help neutralize the challenge from the opposition Labour party, currently just leading the Conservatives in opinion polls, who have promised to introduce a levy, dubbed a "mansion tax," on properties worth more than £2 million ($3.1 million).