Relations between Boris Johnson and Donald Trump have cooled significantly after Johnson’s government allowed Huawei to take part in the roll-out of 5G mobile phone networks despite US objections.

The White House will send a delegation to Britain to press Prime Minister Boris Johnson over Huawei and 5G, The Telegraph reports, citing a source familiar with the plans.

It is understood that the delegation will be led by Mick Mulvaney, Donald Trump’s chief of staff, and will “call for [the British] government to change its position” on whether Huawei should be allowed to build 5G infrastructure in the UK.

The source was quoted as saying that the delegation would give a “b*****king” to the British counterparts.

Boris Johnson last month allowed Huawei to supply non-sensitive parts of infrastructure (such as radio masts and antennas) for the nation’s fledgling 5G networks, despite Donald Trump’s months-long pressure campaign against the Chinese giant.

The US accuses Huawei of secretly using “backdoors” in its equipment to eavesdrop on communications in foreign countries on behalf of Beijing. The company maintains that it had never and would never spy for Beijing. US officials have claimed that they have proof of espionage by Huawei, and that they had passed it to the UK and Germany, though no evidence has ever been shared publicly.

The Trump administration has threatened repeatedly that it would cut crucial intelligence-sharing cooperation with the UK, its key partner in Europe and in the Anglophone Five Eyes alliance, if it opens its 5G door to Huawei.

Multiple US officials have publicly urged the UK to reconsider its decision on Huawei, and there has been word of a highly-charged phone call between Boris Johnson and Donald Trump after the decision was announced, which has been described as “apoplectic”.

In a further reflection of tensions with the United States, Boris Johnson has reportedly postponed his planned visit to Washington until the summer.

It comes as the two allies are negotiating a trade deal; Britain is in a post-Brexit transition period and has until the end of this year to outline its future relations with the United States.

Despite recent assurances from Secretary of State Mike Pompeo that the UK would be at “the front of the line” for trade negotiations, top Trump adviser Larry Kudlow said last week that the US would now prioritise talks with the European Union instead.