European politicians and health chiefs last night criticised Britain's decision to be the first country to approve Pfizer's coronavirus vaccine.
UK watchdogs took just a fortnight to approve the jab following the announcement of successful final trial results.
The Medicines and Healthcare products Regulatory Agency insisted its emergency approval procedure did not cut corners.
Health Secretary Matt Hancock boasted that the Europeans were 'moving a little bit more slowly' due to extra red tape, sparking a backlash from the continent.
But the European Commission said that its European Medicines Agency regulator 'requires a higher level of evidence to be submitted and checked than a temporary use authorisation'.
Former head of the EMA Guido Rasi said: 'I would have expected a robust review of all available data, which the British Government has not done, to be able to say that, without Europe, you come first.'
Peter Liese, who sits on the European Parliament's public health committee, said: 'I consider this decision to be problematic and recommend that EU member states do not repeat the process in the same way.
'A few weeks of thorough examination by the EMA is better than a hasty emergency marketing authorisation of a vaccine.'
But Ben Osborn of Pfizer said: 'We have provided complete data packages, the unblinded data, to both regulators.
'What you're seeing is just the difference in the underlying process and timelines, as opposed to any difference in data submission.'
Matt Hancock (pictured in Downing Street today) boasted that the Europeans were 'moving a little bit more slowly' due to extra red tape - but stressed that the Pfizer BioNTech jab had gone through intense safety checks.
Berlin's ambassador to the UK issued a sharp retort after Business Secretary Alok Sharma said history would remember the 'UK led humanity's charge against this disease'
David Nabarro, a World Health Organisation envoy for Covid, said the MHRA was known for carefully weighing up the risks and benefits of medications and vaccines.
'It is important that everybody realises that on these kind of issues Britain has been looked to by other nations as a country to note carefully,' he told Radio 4's World At One programme:
The EMA is in charge of licensing British vaccines until the Brexit transition period ends next month.
The organisation will decide by December 29 whether to authorise the vaccine from Pfizer and German biotech firm BioNTech. However national agencies can provide rapid temporary approvals in health emergencies.
The EMA and MHRA have long worked closely together, with British experts providing significant input into European decisions.
The UK's Medicines and healthcare Products Regulatory Agency (MHRA) said saying the approval of the Pfizer vaccine (pictured) was made using provisions under European law
Mr Hancock kicked off the row in a round of interviews yesterday, telling Times Radio: 'The reason we've been able to move this fast, and the UK is the first country in the world to have a clinically authorised vaccine, the reason is twofold.
'Firstly, because the MRHA has done a great job of working with the company to look at that data as it's come through and do things in parallel, rather than one after the other as they normally would, that's the first reason.
'The second reason is because, whilst until earlier this year we were in the European Medicines Agency (EMA), because of Brexit we've been able to make a decision to do this based on the UK regulator, a world-class regulator, and not go at the pace of the Europeans, who are moving a little bit more slowly.
'We do all the same safety checks and the same processes, but we have been able to speed up how they're done because of Brexit.'
Mr Liese, a member of Angela Merkel's CDU party, suggested that the move could have been influenced by Prime Minister Boris Johnson's domestic difficulties.
'Britain now has nearly 60,000 corona deaths. Add to this the fact that Britain is an island and has never been a Schengen member, which means open borders in Europe,' he said.
'Britain would have to compare itself more with countries like New Zealand or Ireland, which have a much better grip on the infection rate.'
The EMA suggested that it was imposing more stringent checks than the emergency process used by the MHRA.
At a press briefing, MHRA chief Dr June Raine (pictured) said: 'We have been able to authorise the supply of this vaccine using provisions under European law which exist until January 1.'
A spokeswoman said: 'The temporary authorisation of the vaccine by the MHRA is not a marketing authorisation.
'It differs from marketing authorisations in the level of evidence submitted and checks required.'
The EMA believes that the conditional marketing authorisation (CMA) process is 'the most appropriate regulatory mechanism for use in the current pandemic emergency'.
A CMA application is supported by 'extensive data' submitted by companies and 'provides a controlled and robust framework'.
BioNTech is a German firm and ministers' attempts to portray the approval as a UK success story were criticised by the Berlin government.
Germany's ambassador to the UK, Andreas Michaelis, attacked Business Secretary Alok Sharma's claim that 'in years to come, we will remember this moment as the day the UK led humanity's charge against this disease'.
The diplomat said: 'Why is it so difficult to recognise this important step forward as a great international effort and success? I really don't think this is a national story.
'In spite of the German company, BioNTech, having made a crucial contribution, this is European and transatlantic.'
At a press briefing, MHRA chief Dr June Raine said: 'We have been able to authorise the supply of this vaccine using provisions under European law which exist until January 1.
'Our speed or our progress has been totally dependent on the availability of data in our rolling review and the independent advice we have received.'
Downing Street stopped short of backing Mr Hancock's claim about Brexit.
The Prime Minister's official spokesman said: 'It is clear that we are the first country in the world to approve this vaccine and it is incredibly positive news that we will be able to start to distribute it.'