His ideas, which are mirrored in the EU plans, include exempting defence equipment manufacturers from paying VAT, and applying EU research grants to the sector – a move which could conflict with EU Treaty restrictions on using EU budget for military expenditures.

A timetable for the plan will be discussed at a meeting of 27 EU leaders — excluding Theresa May — at a summit in Bratislava on 16 September.

UK governments have previously opposed the creation of a fully-fledged European army but the European Commission, France, Germany and Italy see Brexit as a new chance to press ahead with deeper EU military integration.

Nato officials have expressed concerns that the proposals will create rivalry and challenge the alliance's primacy as the main defence structure.

Conservative MEP Geoffrey Van Orden, his party’s defence spokesman, said that the “worrying” implications of the EU's defence ambitions were being overlooked in the debate on Brexit and the UK’s future relationship to the EU.

“We can all see that the EU might play a useful role in conflict prevention and in some civil aspects of crisis management. But its ambitions go beyond that. The EU motive is not to create additional military capability but to achieve defence integration as a key step on the road to a federal EU state.