<text>  Allowing council tenants to buy their homes was one of the greatest Conservative ideas of the last century, David Cameron said last night. The Prime Minister pledged to keep backing Margaret Thatchers flagship Right To Buy policy, and said its critics were hypocrites because they were usually homeowners themselves. His comments follow speculation that the Tories want to extend the policy, perhaps by including 2.5million housing association tenants. Harsh words: David Cameron has pledged to keep backing the Right To Buy policy, and said its critics were hypocrites because they were usually homeowners themselves . Work and Pensions Secretary Iain Duncan Smith also wants to reward social housing tenants who hold down a job for a year or more with an automatic stake in their properties. In a pre-election rally in Essex, Mr Cameron said that only his party could be trusted to safeguard the green belt because he is a country man. And he claimed that a Labour government would result in higher borrowing costs; pushing up mortgage cost for families by an extra 1,000 a year. Last night a poll found that the Conservatives have taken the lead over Labour and that voters believe Britain would be burdened with more debt if Ed Miliband wins office. Polling from Lord Ashcroft, a former Tory Party deputy chairman, found that the Conservatives had opened up a two-point lead over Labour. In a pre-election rally in Essex, Mr Cameron said that only his party could be trusted to safeguard the green belt because he is a country man It also found three times as many people believe a Labour government will result in more borrowing and debt than if Mr Cameron remained in office. Speaking at a property firm in Colchester yesterday, the Prime Minister said: We will give more people the chance to own their home by backing the Right to Buy, and more security for those who rent. Right to Buy is one of the greatest Conservative ideas of the last century because its about pure, undiluted aspiration. As Conservatives we dont believe that peoples circumstances need to be stuck in one place forever. If youre out of work you dont have to stay out of work. If youre in poverty you dont have to stay in poverty. If you had a difficult start in life you dont have to repeat the same patterns you were born into. All these things can be overcome with the right opportunities. And that is what Right to Buy is about peoples hard work taking them from being tenants in their home to owners of their home. He added that critics of Right to Buy were invariably homeowners themselves. Whatever some social commentators say, people do have a deep desire to own a place of their own, he said. And its interesting often the people who criticise Right to Buy, who think its unnecessary, are speaking from the comfort and security of a home that they own. Rally: David Cameron applauds a speaker as he prepares to deliver a speech setting out the Conservative Partys sixth manifesto theme at ThinkBDW in Colchester . As Conservatives we dont think its one rule for us and one rule for them. We want to give everyone the chance of owning their own home. So we extended Right to Buy. Thirty-three thousand more people have become homeowners this way, and our Conservative commitment for the next Parliament is to keep on backing this scheme. Mr Cameron also pledged to protect the green belt if the Conservatives win the next election saying he wanted his children to walk on unspoilt countryside such as the North Downs. Building must take place on brownfield land as a priority, he said, but he acknowledged that building could not be restricted to such land. He said Britain is on target to build 200,000 homes a year by 2017 bearing Labours target by three years. When it comes to our Green Belt, I have been clear, he said. The line remains scored in the sand that land is precious. I am a country man. I love our countryside. Put simply: the Green Belt is protected with us. And it is not just green belt that concerns people but green fields. I agree. The Prime Minister also said that a future Conservative government will keep mortgage rates low so that homeowners can go to bed with real peace of mind. Pledging that maintaining low borrowing costs would be the first priority of the Tories housing policy, he attributed the UKs historically low interest rates of 0.5 per cent to his governments deficit reduction programme. He said Labours plan to borrow for investment would result in higher borrowing costs for home owners. And do you know what that could cost people? Just a one per cent rise in market rates would add 1,000 to the average mortgage bill. Britains home owners cannot afford that. So in the next Parliament Conservatives would see through our long-term economic plan, clear the deficit, run a budget surplus by 2018, and help keep mortgage rates low. 