Republican presidential candidate Mitt Romney has denied claims that he did not pay taxes for 10 years.

Senate majority leader Harry Reid accused Romney on the Senate floor of avoiding taxes for a decade, the strongest accusation yet by Democrats in a fight over the former private equity executive’s tax records.

However, Mr Romney strongly denied Reid’s claim, saying the allegation was “simply wrong”.

“I have paid taxes every year and a lot of taxes, a lot of taxes”, he told reporters during a campaign stop in Las Vegas, in Mr Reid’s home state of Nevada.

Mr Romney said the sources of Mr Reid’s accusations may be within the White House or President Barack Obama’s re-election campaign, which has frequently called on Romney to release more than the two years’ worth of tax information that he has made public.

“By the way, Harry, I understand what you’re trying to do,” Mr Romney said.

He accused Mr Reid of trying to deflect attention from discredited policies, and from the Senate’s failure to pass a budget in three years.

Mr Romney did not say which types of taxes he had paid, although financial information he released in January showed he had paid an effective tax rate of 13.9% in 2010, mostly from capital gains on investments. That is far below the 35% top tax rate for wages.

Mr Romney said Mr Reid should “put up or shut up”.

The former Massachusetts governor’s appearance in Nevada came as he tried to regain his footing after a trip to Britain, Israel and Poland that was seen as unsuccessful.

He also faced questions about the tax plan he would attempt to implement should he win election in November.

He insisted that he had no intentions of increasing Americans’ tax burden.

“My plan is very clear,” he said. “I will not raise taxes on the American people.”

Mr Romney also refuted the notion that the richest taxpayers would benefit disproportionately from his plan.

“High income people are not going to pay a smaller share of taxes in America if I am president,” he said.