William Hague has defended the policy changes his party has made over the last four years and said there will be "no vacancy" for party leader after the election.

Speaking on the BBC "Today" programme, the Tory leader said that scrapping his party's opposition to the minimum wage was part of the process of preparing for power.

"If politicians weren't allowed to change their policies during opposition Tony Blair would never be allowed to open his mouth. All of our policies are policies for the next parliament," Hague said.

His comments followed a series of policy u-turns, including the withdrawal of the Conservative tax guarantee, ending opposition to the independence of the Bank of England and tacit support for devolution.

Hague said the party was now more unified behind its policy goals. He said that the party was now speaking with one voice on Europe, despite yesterday's revelation that candidates would be allowed to campaign for a referendum on EU membership.

"The change is that we are committed to being in Europe, and not run by Europe with an overwhelmingly united party," said Hague.

The Conservative leader said he was ignoring opinion poll research and claimed the party was in a better position than in 1997.

"We are doing far better than at the last election. This election is about the opinion of real people - when you go out and meet some real people, they aren't enthusiastic about the government," Hague claimed.

On the question of who would lead the party after the election, Hague said there was "no vacancy" though he agreed that there were a "great many people" who could do the job. He refused to say whether Michael Portillo was one of them.

The Conservative leader is this morning in Peterborough where he is saying that the Tories would "hit crime hard".