Britain's government will set out on Friday the cost of capping energy prices for households and businesses over the next few months to help protect people from soaring power bills, a spokeswoman for Prime Minister Liz Truss said.

The government pledged on Wednesday to cap electricity and gas costs for businesses at less than half the market rate. The finance minister Kwasi Kwarteng plans to make a fiscal statement on Friday to explain his plans to support households and businesses through the coming winter.

"Costs will be set out in the expected fiscal event on Friday," Truss's spokeswoman told reporters. (Reporting by Alistair Smout. Editing by Andrew MacAskill)