The Government has failed to offer reassurance that NHS services can deal with an expected "second wave" of swine flu in the autumn, peers have said.

The House of Lords Science and Technology Committee also criticised ministers for not setting up the National Pandemic Flu Service for England earlier in the year.

An "interim service" is now in operation but was beset by problems when it launched last week, with the website crashing in the first few minutes.

In their report, peers said they were "struck by the number of activities which were only starting up or were still in train in March of this year".

They pointed to the National Pandemic Flu Service as "one very significant example".

The report said: "In November 2008 we were told that the system was 'being delivered and tested in early 2009', a timetable which would have to be reviewed in the event of an increase in likelihood of a pandemic. However, on 27 April 2009, Lord Darzi, Parliamentary Under-Secretary of State at the Department of Health, announced that the flu line would be 'up and running in autumn of this year'."

When peers asked the Government for an explanation of the delay, they were told that development had been put on hold in favour of getting an "interim solution" up and running.

But peers said the evidence about the total call capacity of the centres managing the phone line was "still not entirely clear". It said there were plans for the flu service to have about 7,500 call centre seats. At present, there are about 1,500.

The Department of Health said it was "not confirming details" of how the new service would change from an interim service to a full service in the coming months.

The report also expressed concern about the country's intensive care capacity. But it praised the Government for stockpiling anti-virals like Tamiflu and forming speedy agreements with pharmaceutical companies to supply a vaccine against swine flu.