The Government's Brexit department has spent tens of thousands of pounds on foreign consultancies ahead of the formal triggering of Article 50.

The Department for Exiting the EU (DexEU) started paying civil service salaries to staff from US firm Boston Consulting Group and Accenture, which is incorporated in Dublin and listed on the New York Stock Exchange, months after the Brexit vote, a freedom of information (FOI) request by the Press Association has shown.

They are among eight consultancies that have worked with the department since its creation in July last year - including KPMG, Oliver Wyman, Frontier Economics, McKinsey, Deloitte and PwC - but are the only ones to have been paid more than a nominal £1 fee for their services.

Pro-EU group Open Britain said the move was eating up much-needed cash for public services.

A spokesman said: "They told us leaving the EU would create more money for the NHS, when actually tens of thousands will be spent on outside consultants as our NHS is starved of much-needed funding."

Liberal Democrat leader Tim Farron also took aim at the use of paid consultants, saying it was "a sign of how unprepared and clueless this Government is on Brexit".

He added: "This Government's hard Brexit plans are set to line the pockets of civil servants and consultants while dealing a blow to jobs and living standards for everyone else."

DexEU took on three secondees from Boston Consulting Group to provide "policy development support" on civil service salaries last October. Two are still working for DexEU.

Accenture also provided two secondees for "policy support", but neither are "actively working" for the department.

DexEU refused FOI requests to disclose the salaries of the secondees, saying they were covered by data protection laws.

However, calculations based on civil service salary bands suggest the department may have already spent as much as £79,000 on those five staff alone since the autumn.

A spokesperson for DExEU said: "As you would expect the Government is utilising the skills of the brightest and best across the Civil Service as we prepare to exit the EU.

"It is also quite standard for a Government department to draw on the advice of external specialists and we make no apology for that.

"We will continue to bring in expertise from outside as appropriate."

Deloitte and KPMG only charged a nominal fee of £1, and others including McKinsey, PwC, Frontier Economics and Oliver Wyman offered their services on a pro bono basis.

According to the FOI, those firms offered services ranging from departmental set-up and organisational design, to market analysis and internal financial planning.