Downing Street has defended climate change minister Alok Sharma for visiting 30 countries this year, insisting that face-to-face meetings with foreign leaders are “essential” in his role as COP26 president.

Mr Sharma has come under fire after it emerged he has flown to 30 countries this year – including six on the government’s Covid red list – without isolating on his return.

More than half of the trips took place while international travel was all but banned for Britons, according to an audit by the Daily Mail.

Mr Sharma, who is currently visiting Bolivia and Brazil – both red list countries – is tasked with securing commitments from key countries as he prepares to host the climate change summit in Glasgow this November.

But Downing Street defended his travel record and said it was within the rules for him to avoid quarantine on his return to the UK.

Prime minister Boris Johnson’s official spokesman said: “As COP president, Alok Sharma is leading climate negotiations with countries including major emitters to cut emissions and secure ambitious action ahead of the COP26 summit.

“The majority of this work is done remotely but some travel to key countries for face-to-face talks is essential.

“He has secured ambitious action as a result of the discussions he has had. For example, immediately following his visit to Japan and South Korea the governments there committed to ambitious net zero targets, which was a key ask from the UK.”

The spokesman added: “Ministers conducting essential travel such as this are exempted from quarantine, as set out in the rules.”

Asked if he would quarantine on his return from Brazil, the spokesman said: “He will continue to comply with the rules as set out.”

Mr Sharma’s previous red list trips include Qatar, the UAE, Bangladesh and Turkey.

Instead of the mandatory hotel quarantine faced by anyone entering the UK from red list countries since February – the cost of which has just risen from £1,750 to £2,285 – Mr Sharma used a ministerial exemption available to “Crown servants” such as diplomats and essential workers.

The exemption requires a negative Covid test.

Days after returning from an early June trip to Bangladesh, Mr Sharma met the Prince of Wales indoors before visiting a primary school.

The Daily Mail also reported Mr Sharma was able to avoid having to isolate at home following his return from amber list countries.

Sarah Olney, the Liberal Democrat transport spokesperson, told the newspaper: “As usual with this government, it’s one rule for them and another for everybody else.

“While Alok Sharma flies to red list countries with abandon, hard-working families can hardly see loved ones or plan holidays as the government changes travel rules on the hoof.”

And Labour shadow cabinet minister David Lammy told LBC: “That’s hugely worrying. The lack of self-isolation is bizarre and dangerous. It is probably impossible not to fly, of course, but I think he should be leading by example clearly.”

Green Party peer Baroness Jones of Moulsecoomb added: “I do understand it’s very good to meet people in person, but this is excessive. When you’re in charge of COP26, to take this many flights is hypocritical.”