Mr Dobson has written to the Daily Mail newspaper, while at the same time a Cabinet colleague and the prime minister's official spokesman dismissed accusations that ministers were indulging in lavish lifestyles.

Downing Street has indicated it will take an "aggressive line" towards any further questioning about ministers' overseas travel arrangements.

Frank Dobson: "Merit in meeting colleagues"

The prime minister's official spokesman accused the opposition and the media of pursuing a trivial agenda.

In a letter to the newspaper, Mr Dobson defended his decision to travel to Barbados in mid-November for a three-day conference of Commonwealth health ministers.

He wrote: "This was long before there was a flu epidemic and at a time when the NHS waiting lists fell by 31,000 in just one month.

"It was my first opportunity to meet my opposite numbers from the Commonwealth and I used it to hold a series of meeting with my counterparts."

Mr Dobson said the meeting had helped to promote the export of UK health products as well as providing useful discussions on anti-Aids and anti-malaria programmes.

The health secretary wrote: "I also believe there is always merit in meeting colleagues from other parts of the world to swap ideas and experience and because it promotes our influence in the world affairs.

"In line with ministerial rules, I travelled business class both ways and stayed at the conference hotel. On the trip out, I re-drafted our white paper on tobacco, I slept all night on the way back."

The letter continues: "I left the conference a day early and did not take part in any cruise, go swimming or sunbathing."

He also pointed out that the last three conferences were in Cape Town, Cyprus and Sydney and were all attended by Conservative ministers.

Mr Dobson wrote: "As the prime minister said recently, we have a choice in this country.

'Concorde Jack'

"We can either have politics run on the level of gossip with the media trying to turn everything into a scandal or we can have a government getting on addressing the real problems facing this country."

In the Commons, Chief Secretary to the Treasury Alan Milburn rejected criticism from both Labour and Tory MPs that ministers were enjoying the high life.

Jack Cunningham: Concorde flights defended

Veteran Labour backbencher Dennis Skinner said: "Some of us on this side of the House are not very happy about the way in which people want to live the high life and fly in Concorde and all the rest of it."

Tory John Wilkinson accused Chancellor Gordon Brown of abandoning "frugality" and "chartering aeroplanes and helicoptering around" as well as dubbing Cabinet Office Minister Dr Jack Cunningham "Concorde Jack".

Mr Milburn insisted: "There are very strict rules governing this issue.

"We abide by those rules and they are the same rules that applied when the Conservative party were in government."

Prime Minister Tony Blair's official spokesman called the whole row over Concorde trips "ridiculous".

He said the Tories spent between £6.5m and £8m a year on overseas travel in their last three years in power while the government spent £5.6m in its first year and on current trends will spend about £4m this year.