Mr Cameron said he had treated his MPs "fairly and robustly"
Tory leader David Cameron has defended expenses claims for his second home and said he would do the job for "half the money, twice the money or no money".
But Mr Cameron denied he had used the expenses row as a way to get rid of long-serving "grandees" in his party.
He told BBC Radio 2's Jeremy Vine Show: "What we have done is not perfect but at least we have paid the money back."
Mr Cameron also said he had called for future MPs' expenses to be published without blacking out large sections.
The Conservative leader has been the subject of press reports about his claims for mortgage interest on his constituency home in Witney, Oxfordshire.
But he insisted that he was in politics to serve the public and said he hated the fact that UK politics had been "dragged through the mud".
He said: "Frankly, I love this job because I love doing public service, working for my constituents, trying to hold the government to account, hopefully one day leading a government.
"And I've tried, as a party leader, to be tough, to help clean up the system and to show that the Conservative party, at least, absolutely gets why the public are so damn angry."
However, Mr Cameron denied he had used the scandal to target Tory grandees.
He added: "I have tried to behave fairly and robustly with all my MPs."
According to the Mail on Sunday, Mr Cameron paid off the remaining £75,000 of a mortgage on his London home using his own money in 2001, shortly after taking out a £350,000 mortgage on his constituency home.
The newspaper said he could have saved taxpayers money by paying off some of his constituency mortgage instead, but Mr Cameron did not break any rules and has always insisted that taxpayers had not lost any money as a result of his actions.
Mr Cameron has also repaid £947.29 in expenses, including £680 in maintenance costs and £267 claimed as a result of "inadvertent error".