The Public Accounts Committee asked Nigel Crisp, chief executive of the NHS, about a survey of 1,500 GPs published last week by public spending watchdog the National Audit Office.
It showed GPs had a better knowledge and understanding of Choose and Book since the NAO carried out a similar survey in 2004. But the vast majority of GPs had a negative view of the scheme, and 61% said they would not be willing to offer patients a choice of four or five hospitals - the target set by the government.
About 50% of GPs said they did not have the capacity to implement Choose and Book in their practice.
Crisp replied that the figure of 61% was "a serious matter and one we want to be able to question". But he was otherwise positive about the survey's results. "As GPs start to use the programme, we start to see the enthusiasm for it growing," he said.
But Edward Leigh, chairman of the Public Accounts Committee, contradicted him. Pointing to the specific results of the NAO survey, Leigh said doctors were becoming more negative about the scheme as they became more aware of it. "Does this suggest that the programme doesn't seem to be working?" he asked.
Crisp replied that all the evidence he was getting suggested a big increase in the use by GPs of Choose and Book.
MP Richard Bacon said his personal details had been looked up on national systems by a GP and the address was 23 years out of date.
John Bacon, overall senior responsible owner of the NHS IT programme, replied that his team wants to ensure that data is kept clean and is constantly updated.
The committee's report on Choose and Book will be published in 2006.