The Indian firm was reportedly furious after details of private correspondence from Lord Mandelson addressed to them appeared in a Midlands newspaper.

The company owned by Tata Motors, headed by Ratan Tata, has itself waged a media campaign, accusing the Government of demanding a hands-on role in the running of the company in return for the loan guarantees.

The 300 Halewood job losses were announced last month when plant bosses confirmed the “Baby Jag” would cease production at the end of the year.

The popular Freelander 4x4 model is still produced at the factory, with the possibility of a future seven-seater version.

But the big hope for the Knowsley plant rests on the concept LRX car, a “Baby Land Rover” which will achieve an environmentally-friendly 60 miles per gallon.

Following the lengthy negotiations to reach this point, a final agreement between Whitehall and Tata on the loan deal may not come until later in the month.

According to figures recently released by the Liberal Democrats, nearly 10,000 UK car industry jobs have been lost since the Government announced its automotive assistance programme in January.

The party said the figures related to Government statistics of notifications of proposed redundancies received between January 1 and June 18.

Liberal Democrat business spokeswoman Lorely Burt said: “The car industry has been knocked for six by the recession.

“Since the start of this year, 10,000 UK jobs have gone.

“Six months ago the Government trumpeted a £2.3bn automotive assistance programme that would help ‘green’ UK car manufacturing and secure jobs.”

A spokesman from the Department for Business said the Government is committed to supporting the sector through the downturn and a move towards a low carbon economy.

He said: “The scrappage scheme has seen over 134,000 orders since it was launched and Nissan has been recruiting more workers to cope with the extra demand.”