Iain Duncan Smith has pressed the government to issue a more accurate assessment of the number of people on NHS waiting lists.

Speaking during prime minister's questions, the Conservative leader asked whether it was right that "NHS patients waiting for tests for illness like cancer or heart disease should be excluded from the official waiting list figures as they are right now?".

Tony Blair said the figures were the same now as they were under the previous government

"We are applying the same tests in exactly the same way" he said.

But the Tory leader responded that there are at least 250,000 people waiting for tests and scans and that hospitals already collect the data.

He told the House: "Why doesn't he now instruct his health secretary to include these people on the waiting lists as they should be?"

Blair reiterated that the figures were complied "in precisely the same way that they have always been done".

There are now more operations and more highly skilled doctors, he claimed.

"There is much more that needs to be done...our response to that is to invest in the national health service," said Blair.

"Will he please now tell us what he wants to see?"