Britain must develop a ‘Four Eyes’ intelligence sharing alliance in response to Donald Trump’s actions over Ukraine, defence sources have said.

The US President’s ‘unprecedented’ decision to block allies, including the UK, from giving Ukraine US-generated classified material that could benefit the eastern European country has sparked calls for a breakaway group.

Mr Trump used his powers as part of the ‘Five Eyes’ alliance of the US, Britain, Australia, Canada and New Zealand to suspend intelligence to Kyiv.

Some in the defence establishment are now suggesting forming a sub-group to allow intelligence sharing without a US veto. 

‘It isn’t about pulling out of Five Eyes, it is about creating a new “Four Eyes” within it – without America,’ a source said.

The US’s decision would ‘damage Ukraine’s ability to defend itself against ongoing Russian attacks’, the Institute for the Study of War said last week.

Former British ambassador to Washington Sir David Manning said the question of intelligence sharing was going to be ‘more difficult to approach’.

Donald Trump suspended intelligence sharing with Ukraine using his powers as part of the ‘Five Eyes’ alliance 

Former British ambassador to Washington Sir David Manning said there is a ‘big question mark’ over how to sustain the special relationship during the Trump administration and that intelligence sharing was going to be ‘more difficult to approach’

He told MPs last week: ‘Clearly, if you have some Trump supporters in these key jobs who have very strange track records and have said very strange things about Nato allies and the Nato alliance and you have people in the administration who seem to be looking for ways of appeasing Russia, then you have a problem on the intelligence front.

‘That is a big question mark against how the special relationship is sustained during the Trump administration.’

A Government spokesman said: ‘We have a deep and long-standing defence

and intelligence relationship with the US and we continue to work closely with our Five Eyes partners.’