LONDON (AFP) -- David Cameron said Sunday he wanted to serve as British prime minister until at least 2020 to oversee a range of reforms including a renegotiation of Britain's relationship with Europe.

In a raft of interviews ahead of a midterm review of the progress of his coalition government on Monday, Cameron also defended a largely unpopular decision to remove child benefit payments from higher earners.

Cameron told the Sunday Telegraph he intended to lead his Conservative Party to victory in the 2015 general election and then serve a full five-year term.

As Cameron rarely speaks about his planned departure date, it has prompted speculation that if re-elected he would stand down halfway through his mandate.

But when asked by the newspaper if he intended to stay on as prime minister until 2020, Cameron said: "I want to fight the next election, win the next election and serve -- that is what I want to do."

Pressed on what he would say in a major speech on Britain's strained relationship with the European Union that he is due to give in mid-January, Cameron said his party would offer voters a "real choice" at the 2015 election.

He said any vote on Britain's relationship with the EU would happen in the five years after the election, but he refused to be drawn on whether a poll would include the question whether Britain should remain in the bloc.

"People should be in no doubt that the Conservatives will be offering at the next election a real choice and a real way giving consent to that choice," he said in an interview on BBC TV.

He stressed it was in Britain's economic interest to remain a full member of the EU to enable the country to influence the direction of the single market.

"If we were outside the EU all together, we'd still be trading with all these EU countries, but we'd have no say over the rules of the market into which we sell," Cameron said.

He said that because the countries using the euro were forced to make changes to their relationship to bolster the currency, Britain was "perfectly entitled" to ask for changes to the conditions of its membership.

On the domestic front, Cameron insisted there would be no u-turn to a move due to kick in on Monday to remove child welfare payments from families in which one parent earns more than 60,000 pounds ($96,430).

Defending the government's latest bid to slash the deficit through cuts in public spending, Cameron said: "I'm not saying those people are rich, but I think it is right that they make a contribution.

"This will raise 2 billion pounds a year. If we don't raise that ?2 billion from that group of people -- the better-off 15 percent in the country -- we would have to find someone else to take it from."