The UK's access to Europe's SAFE defence fund is vital to deter "the tyrant on our doorstep", campaigners have stressed, following reports that negotiations over Britain joining the first round of the €150 billion fund have failed.
It comes after talks ended without a resolution following the European Commission originally seeking payments of up to €6.75 billion from the UK to join Security Action for Europe (SAFE).
The UK's counter offer of a financial contribution of €82 million was rejected by Brussels, Bloomberg reported.
EU minister Nick Thomas-Symonds confirmed the development, stating: "While it's disappointing that we have not been able to conclude discussions on UK participation in the first round of SAFE, the UK defence industry will still be able to participate in projects through SAFE on third country terms."
Naomi Smith, chief executive of Best for Britain, which campaigns for closer UK-EU ties, said:
"In Ukraine, brave men and women stand between us and the tyrant on our doorstep. With Trump putting Zelenskyy under intense pressure to capitulate to Putin’s demands, now is not the time for bureaucratic wrangling.
"It is the time for liberal democratic allies across the EU who are serious about defending freedom and deterring aggression to get their act together, secure UK access to SAFE, and prioritise keeping our continent secure. After all, ensuring lasting peace was the EU's founding rationale."