David Davis has rejected suggestions that the UK will foot a €100bn (£84.5 billion) Brexit bill, saying Brussels will only receive what it is legally owed.
The Brexit Secretary said the European Commission could not set a "divorce deal" figure and dismissed as "laughable" reports that Prime Minister Theresa May would be barred from negotiating with her counterparts.
It had been believed Brussels was seeking up to €60bn (£50.7 billion) for Brexit, but added demands by the EU could send the figure soaring, according to the Financial Times.
The UK could receive calls to contribute to post-Brexit farming payments and may be blocked from obtaining a share of EU assets, the FT said.
But Mr Davis said the UK had not been presented with a consistent sum for its impending departure from the bloc.
"It was 50 billion at one point, 60 billion, 100 billion, we have not seen a number," he told Good Morning Britain.
"We have said we will meet our international obligations, but there will be our international obligations including assets and liabilities and there will be the ones that are correct in law, not just the ones the Commission want.
Pressed on reports that the eventual divorce figure could reach up to 100 billion euro, he said: "We will not be paying 100 billion."
He added: "We will do it (negotiate) in the meeting, we will do it properly, we will take our responsibility seriously.
"What we've got to do is to discuss in detail what the rights and obligations are."
He also claimed the EU could not bar the Prime Minister from joining Brexit discussions at future EU heads of government meetings while the UK remained a member state.
According to reports, Brussels was plotting to limit Mrs May's Brexit discussions to direct meetings with the European Commission's lead Brexit negotiator, Michel Barnier.
Such a move would run contrary to Mrs May's claim that she would be negotiating directly on the terms of Brexit with fellow European leaders.
Mr Davis told the programme: "The decisions in this exercise at the end of the day are taken in Council - that's a gathering of all the leaders of the European Union - and, frankly, until the day we leave, we are full members of the Union, we have every right to attend every Council and we will exercise our right.
"Just as we are obeying the laws of the Union, exactly to the letter, we are also going to expect our rights.
"The idea that somehow one side of the negotiation can dictate how the other side runs a negotiation is laughable.
"This is an exercise in trying to shape public opinion and trying to pressurise us - it won't work."
After reports that a meeting between Mrs May and European Commission president Jean-Claude Juncker in Downing Street last week had seen tense moments, the PM appeared to toughen her stance.
Mrs May boasted on Tuesday about being a "bloody difficult woman", with the Brexit Secretary agreeing on Wednesday that she was "tough-minded and decisive", after she dismissed the leaked account of the dinner with Mr Juncker as "Brussels gossip".
The Prime Minister told the BBC: "During the Conservative Party leadership campaign I was described by one of my colleagues as a bloody difficult woman.
"And I said at the time the next person to find that out will be Jean-Claude Juncker."
Tory MP Sir Bill Cash told the Daily Telegraph he believed Germany and the EU were trying to influence the General Election, saying: "What they are doing is trying to exploit a new kind of Project Fear and that is not going to work on the British people."
Brexit looks likely to again be a major political talking point in the election campaign as Mr Barnier gives a press conference on Wednesday.
Mr Davis insisted the UK would get a deal and dismissed reports about negotiating problems as a "mixture of gossip and spin", saying that the majority of EU leaders were supportive of Britain.
Speaking on BBC Radio 4's Today Programme, he said: "In the walkaway circumstance, there is nothing to be paid.
"Nobody is looking for that outcome, that's the important point to be made. I don't want people listening to this programme to leave thinking this is what we want to do - we don't.
"We want a deal, we think we can get a deal and we will get a deal that is beneficial to everybody."
He refused to be drawn on weekend reports that EU leaders thought Mrs May was "from another galaxy" and insisted she was the right person to lead on Brexit.
Mr Davis said: "This negotiation will last up to two years and this the first part where we will have this slight rough-and-tumble approach.
"That actually is a very good demonstration of why, what do you call her - 'the bloody difficult woman?' ... our Prime Minister, Theresa May, is exactly the right person to do this.
"She's decisive, she's tough, they know her, they respect her, and that's the choice the British public has got before them today. Her leading negotiations or Jeremy Corbyn."
Responding to Mr Davis's comment that the UK would not pay a 100 billion euro divorce bill, Liberal Democrat leader Tim Farron said: "This is the latest unpaid bill by the Brexiteers.
"I guess they have thrown it on the pile with the £350 million per week for the NHS.
"During the referendum no divorce bill was ever mentioned.
"Then it was 50 billion and now it's leaped to 100 billion.
"If that is Theresa May's negotiating skills, doubling our bill after one meeting, we should all be deeply worried.
"This bill adds greater strength to the Liberal Democrat argument that we need a referendum on the deal."