There were any number of political / trade union / military types queuing up before the Referendum to remind everyone, categorically, that the Royal Navy does not buy warships made outside the UK, and that it would not do so in the future. We only buy British.
This conveniently overlooked the fact that there's no military-industrial base in the UK that's actually capable of building an entirely home grown warship. Let's have a look at the the current pride of "British shipbuilding", the Type 45 Destroyer. This was built with steel from an Indian-owned steel company, has a Franco-Italian missile system, a Dutch search radar, Finnish diesel engines, Franco-American electric propulsion motors, Anglo-Franco-American main gas-turbines, Anglo-American sonar, American navigation radars and systems, an American ship operating system, American anti-ship missiles, American and Swiss light weapons and an Anglo-Italian helicopter. But we only buy British.
This is not at all surprising actually, the Americans are probably the only nation who have the military-industrial base to do most everything home grown. The big defence companies are all multinationals (BAE systems has more operations outside the UK than in it). The UK and most other European nations have been collaborating with each other and the US, and buying each others bits and pieces of kit to stick on their ships for years. But we only buy British.
The Royal Fleet Auxiliary (the MoD-owned, merchant-manned naval support service) is full of ships that were foreign built, including their latest and flashiest fleet replenishers which are coming from Korea. But these aren't strictly speaking warships, they are just military owned ships without with the Royal Navy's Warships can't go to war so we still only buy British.
There were lots of proud pro-UK pictures of the ceremony naming the new aircraft carrier at Rosyth, with the big blue gantry crane required to assemble the thing in the background. The press and No-sayers were all very quiet on the fact it had to be bought in from China... But of course an rUK would never have bought a Scottish crane to build warships, after all, they only buy British when it comes to Warships.
So really what the categorical assertion came down to is we only assemble multinational components into warships in the UK. Up until now. With some exceptions..
This all may come across as a bit of schadenfreude, but I assure you it's schadenschaden.