Health Secretary Jeremy Hunt has hit back at accusations that Theresa May has been too "timid" in her approach to the Brexit negotiations.
His intervention came amid renewed turmoil within the Tory Party after Chancellor Philip Hammond suggested the UK and the EU were only moving "very modestly" apart in trade terms.
In a speech on Thursday, the leading Brexiteer Jacob Rees-Mogg warned the Government's "timid and cowering" approach risked squandering the potential gains of leaving the EU.
However, Mr Hunt told the BBC Radio 4 Today programme: "Anyone who uses the word 'timid' about this Prime Minister is absolutely wrong.
"This is the Prime Minister that gave us absolute clarity after the Brexit vote that we were going to get back control of our laws, our borders, our money - the most profound strategic decision any prime minister has to make in the current circumstances."
Mr Hammond's comments, at the World Economic Forum in Davos, drew a rebuke from Downing Street where a senior source said leaving the single market and the customs union could not be described as "very modest changes".
However, Mr Hunt said the Chancellor was simply trying to make the point that the UK was well-place to negotiate a free trade deal which resulted in "very limited" changes to its access to EU markets.
"The point that Philip Hammond was making which has been slightly overshadowed is that we start in the unique position with the EU of total regulatory alignment and that actually makes it much easier to negotiate," he said.
"Normally when you have a free trade deal the thing that makes it difficult and takes a long time is where regulations diverge and people have to come to a deal about where they are going to come together.
"We actually start with 100% alignment and that means - and this is the crucial point that he was making - is that we should be able to expect very limited and possibly no changes to market access as a result of the free trade deal we negotiate. That is something we can be very positive about."
In a speech on Friday, Brexit Secretary David Davis will seek to reassure Tory Eurosceptics that the UK will exercise its independence as soon as the country leaves the EU.
He will insist that Britain will be able to sign trade deals with other countries during the transition period after leaving the EU in March 2019, despite being largely tied into Brussels' rules during a two-year post-Brexit transition.
Speaking in Middlesbrough, he will say: "As an independent country, no longer a member of the European Union - the United Kingdom will once again have its own trading policy.
"For the first time in more than 40 years, we will be able to step out and sign new trade deals with old friends, and new allies, around the globe."
While the UK will replicate the effects of the EU customs union during the "implementation period", this "should not preclude us from formally negotiating - or indeed signing - trade agreements".
Any such deals would enter into force at the end of the implementation period.