European governments are being warned that Britain may in future hold back military help for EU countries if there is a no-deal Brexit, HuffPost UK understands.

Officials have told foreign diplomats that while Theresa May is fully committed to maintaining strong defence and security ties, future governments could be less willing to support new missions in the EU like the current deployment of troops to Estonia, on Russia’s border.

At the beginning of Brexit talks, Britain’s defence and intelligence capability was widely seen as a potential trump negotiating card, and the revelation comes as the prime minister scrambles to win EU concessions on her Brexit deal. 

However, government insiders insist the warnings are not part of any negotiating tactic, but instead an illustration of how poor and potentially adversarial trade links could lead to a deterioration in bilateral relations.

Fears that a no-deal Brexit could usher in a more isolationist Jeremy Corbyn-led government that could drastically reduce the UK’s global military commitment could also be a factor in the briefings.

It comes after Foreign Secretary Jeremy Hunt warned in a Washington speech last year that a “messy divorce” would fracture relations with the UK and amount to a “geostrategic error for Europe at an extremely vulnerable time in our history”.

In her landmark Lancaster House speech in January 2017, May was keen to highlight that Britain and France were the EU’s only two nuclear powers and that the UK’s intelligence capabilities were “unique in Europe” and had “saved countless lives” across the continent.

The PM has maintained that Britain was unconditionally committed to European security.

But May was accused of “blackmail” by the European Parliament’s Brexit coordinator Guy Verhofstadt after saying in her Article 50 letter to trigger Brexit in March 2017 that “a failure to reach agreement would mean our cooperation in the fight against crime and terrorism would be weakened”.*

Commons home affairs committee chair Yvette Cooper also stressed at the time that May “should not be trying to use this as a bargaining chip in the negotiations”.

Hunt on Wednesday was visiting Poland for bilateral talks with Prime Minister Mateusz Morawiecki which touched on Brexit as well as the Yemen conflict and the situation in Iran.

Poland is seen as one of the UK’s closest allies in the EU and the two nations in December agreed a joint EU-UK treaty on defence and security cooperation.

The foreign secretary also travelled to France, the EU’s other big military power, on Tuesday to meet his counterpart Jean-Yves Le Drian, and Europe Minister Nathalie Loiseau.