MANCHESTER, England — Sensing a chance to occupy the political center ground in his final term in office, Prime Minister David Cameron of Britain on Wednesday pledged to battle discrimination, fight for equality, help the poor find housing and make an “all-out assault on poverty.”

Closing the Conservatives’ first party convention since their election victory in May, Mr. Cameron returned to ideas he championed when he first won the leadership of his party in 2005, emphasizing a “modern, compassionate” conservatism that offered help to the destitute and opportunity to those who want to better themselves.

He wants his period in power to be remembered as a “defining decade for our country,” a “turnaround decade,” he said, “when people no longer felt the current going against them, but working with them.”

Mr. Cameron appears to have identified the political center as his for the taking, after an election victory in which the centrist Liberal Democrats, who had been in a coalition with the Conservatives, slumped to just eight seats in Parliament, and after the opposition Labour Party, which lost Scotland and did poorly in England, swung to the left.