Theresa May's new Brexit department has spent tens of thousands of pounds on legal advice in the eight weeks since its creation, according to official figures.
Britain has yet to formally start talks to withdraw from the European Union, with the Prime Minister and Brexit Secretary David Davis coming under fire for revealing little detail about their plans to MPs.
But the Department for Exiting the European Union said its legal bill has so far reached an estimated £268,711 - an average of around £33,500 a week.
Officials are still assessing the total amount of taxpayers' cash required for legal advice over the next 12 months when the UK Government is expected to have invoked Article 50 of the Lisbon Treaty, thereby triggering what is predicted to be a complex two-year negotiation process.
The department came into existence in mid-July after a majority of voters backed Britain's withdrawal from the EU in the June 23 referendum.
Mrs May put Mr Davis into a position of power alongside fellow Brexiteers Liam Fox, now International Trade Secretary, and new Foreign Secretary Boris Johnson in a move viewed as an attempt to allow those who backed withdrawal to play a major role in finding solutions.
The PM was viewed as a reluctant Remain backer during the referendum campaign although she is now seeking to convince Leave voters that she will honour their desire for Brexit in full.
Brexit Minister David Jones, replying to a written parliamentary question from former Liberal Democrat leader Nick Clegg, said: "The department is currently assessing the overall requirement for legal advice and the associated funding requirement over the next 12 months.
"To date, the department has incurred an estimated total of £256,000 in fixed-fee legal advice with the Government legal department and a further £12,711 in relation to additional billed fees and disbursements.
"No spend has been incurred in relation to external legal firms."
Lib Dem MP Mr Clegg, who has returned to frontline politics as his party's EU spokesman, asked the Brexit department to reveal how much it has spent on internal and external legal advice, plus a prediction of future spending in the year ahead.
Mr Clegg told the Press Association: "Anyone who thinks Brexit will be quick or easy is seriously mistaken.
"This huge taxpayer-funded Brexit bill for legal advice shows how ill-prepared Whitehall is for what will be the biggest and most complex set of negotiations it has ever attempted.
"But it is not just legal advice where the Government is ill-prepared - we simply don't have anything like the number of trade negotiators necessary to establish a new trading relationship with the EU or other countries.
"The process of leaving the European Union, regardless of what deal the Government eventually agrees, will be long and painful and risks a long period of uncertainty for British business, jobs and our wider economy."
Mr Fox told MPs on Thursday morning that he was not looking to create "a standing army of bureaucrats" to negotiate Brexit.
"My department already has a strong and capable trade policy team, which has doubled since June the 23rd," he said.
"In the next two years we will be developing that team to build the world-class negotiating strength needed to deliver the best outcomes for the UK.
"In terms of negotiators, we have already had strong expressions of interest from individuals, organisations and governments."
Lib Dem Tom Brake pressed Mr Fox on whether the department would be hiring scores of consultants.
He added that a headhunter he had spoken to said a consultant at the head of this team would cost in the region of £750,000 a year.
But Mr Brake's discussions with a headhunter prompted laughter on the Government benches, as they questioned his intentions for speaking with them.
"It's nice to see the Lib Dems are looking forward to repeating the election success at the next election that they've just had," Mr Fox joked.
"I always think it's nice for politicians to cover all their options."
Mr Fox added: "We are not intending to create a standing army of bureaucrats that would be expensive to the taxpayer.
"We're looking to see how most effectively we can create the skills and the calibre of negotiators we would require."