Theresa May has ordered officials to start work on a British satellite-navigation system to rival the EU’s Galileo, in a show of strength as Brussels threatens to block the UK from its project.

The Telegraph understands that Philip Hammond, the Chancellor, has signed off funding amounting to as much as £100 million to "map out" plans for a post-Brexit UK satellite system, with an official announcement due this week.

The disclosure comes after European Commission claimed that to allow continued UK involvement in Galileo after Brexit would threaten the EU's security.

Graham Turnock, Chief Executive of the UK Space Agency told this newspaper that it looked increasingly unlikely that Europe would change its mind and grant access to Galileo, or allow British contractors to bid to help build future satellites.

Earlier this summer it emerged that some ministers were pushing for funds to begin work on the feasibility of a UK satellite-navigation system, amid the growing row with Brussels over access to Galileo.