Britain has failed to make meaningful progress towards a free trade deal with the United States amid “chronic” staffing shortages and communication breakdowns in Whitehall, according to a cache of documents seen by The Telegraph.

Details of meetings spanning two years show how overstretched departments have been working “at cross purposes” as transatlantic talks have repeatedly stumbled over politically sensitive topics such as rules on health, farming and the finance industry.

Officials have begun to fear that American frustration with the lack of agreement or even partial agreement could end hopes of a post-Brexit partnership envisaged at the centre of a “global Britain” trade strategy.

In one message a British diplomat warns that this week’s visit to Washington DC by Liam Fox, the trade secretary, could look like a “bit of a desperate bid” to demonstrate progress.

The cache of correspondence and memos shows gradually rising concern among officials about Britain’s ability to conduct such complex negotiations.

The documents bring further scrutiny to a relationship under strain following the leak of criticisms of the Trump administration by Sir Kim Darroch, the British ambassador to the US.

His resignation on Wednesday prompted anger across Whitehall over a perceived breach of diplomatic norms. Meanwhile it is understood that the US cancelled a planned meeting between Dr Fox and Mr Trump’s commerce secretary Wilbur Ross.