British Prime Minister Liz Truss said on Wednesday she was against imposing a windfall tax on energy companies to help tackle an energy price crisis, repeating that she will make sure her plan will help people and businesses.

Speaking at her first prime minister's question time in parliament, Truss said she would announce her plan to help people pay spiralling energy bills on Thursday.

"I am against a windfall tax. I believe it is the wrong thing to be putting companies off investing in the United Kingdom," Truss said. (Reporting by William James, writing by Elizabeth Piper)