Titled "Brexit Update," the memo, obtained by "The Times" and cited by the BBC on Tuesday, said government departments were working on more than 500 Brexit-related projects and might require an additional 30,000 civil servants.

According to the document, the government had failed to reach a common Brexit strategy due to ministerial divisions. Foreign Minister Boris Johnson, Trade Minister Liam Fox and Brexit Minister David Davis are said to be on one side, while Finance Minister Philip Hammond and Business Minister Greg Clark are reportedly on the other.

Dated November 7, the memo also criticizes Prime Minister Thersea May for her tendency of "drawing in decisions and details to settle the matter herself."

May's office said it did not recognize the claims made in the memo, however.

"This is not a government report and we don't recognize the claims made in it," a spokesman for May's office said. "We are focused on getting on with the job of delivering Brexit and making a success of it."

As well as highlighting government divisions, the memo also claims that "major players" in industry were also likely to "point a gun at government's head" to secure post-Brexit assurances. This follows carmaker Nissan publicly requesting clarity from the government regarding Brexit and then subsequently committing to major investment in the UK's northeast, without divulging what Downing Street had said to quell its concerns. 

Parliament to vote on Brexit

News of the leaked memo on Tuesday was just the latest chapter of pandemonium in the UK's impending departure from the EU.

In a shock result in the June 23 referendum, 52 percent of the UK voted in favor of leaving the bloc. In a landmark decision earlier this month, however, the UK High Court ruled that parliament must be given a vote before the government can start the formal process of exiting the EU.

The ruling sparked fears among Brexit supporters that triggering Article 50 of the Lisbon Treaty and consequently beginning the process to leave the EU could be delayed beyond the March date promised by Prime Minister May. Experts have also said that the High Court verdict could allow lawmakers to soften the government's approach to negotiations. Without explicitly stating her strategy or approach for the talks, May has hinted more than once that she would not compromise on the issue of border control, but has also said she would like to retain as much access to the European Single Market as possible.

Now faced with a parliamentary vote, May has sought to reassure EU leaders, telling German Chancellor Angela Merkel and European Commission President Jean-Claude Juncker that she believed the government's appeal would win in Britain's Supreme Court - removing the need for parliamentary approval.

On the continent, however, patience is wearing thin. During a meeting with his British counterpart in Berlin, German Foreign Minister Frank-Walter Steinmeier said talks between the UK and the EU needed to begin quickly even if the High Court ruled that the British parliament must be consulted.

"Further delay isn't in anyone's interests," Steinmeier said.