This proposal has resurfaced after many believed it had sunk without trace many months ago.
It seems that someone wants to keep the idea afloat.
Yes it's a piece about navies and submarines so I couldn't resist it.
The story has made it into the press again this week with dark undertones that a deal may have been struck over this by Gordon Brown and President Sarkozy in 2008.
Soon after a meeting between the two, President Sarkozy said in a speech "Together with the United Kingdom, we have taken a major decision: it is our assessment that there can be no situation in which the vital interests of either of our two nations could be threatened without the vital interests of the other also being threatened.
" It could be then that this idea is far more advanced than is let on.
But I cannot get away from the notion that to do this properly there would have to be a joint French / UK input into the nuclear firing chain right from the top where the decision is made to the finger that pushes the button or pulls the trigger on the submarine.
That would mean a co-ordination of foreign policy.
The weapons of both countries would need identical targeting.
Coding and communication systems to be synchronised.
On both sides foreigners would surely need to be given access to the most sensitive of national information.
There would need to be a contingent of Royal Navy personnel serving at sea with the Force de Frappe (strike force), while the Marine Nationale (La Royale) would have their sailors at sea on patrol on board a Vanguard class submarine.
When sailing a modern submarine it is not just a case of throwing the ropes over the side, pushing out to sea then opening a few valves.
It is a complicated and dangerous environment unless everyone knows exactly what they are doing and has intimate knowledge of the craft they are in.
Submarines, even the largest ones, are not spacious enough to carry passengers.
So all on board would have to be active involved members of the crew.
Fighting units like submarines are more effective (and safer) when they have a knowledgeable and well trained crew.
That means language barriers have to be overcome.
Not only that both sides would inevitable have to relinquish radar, sonar, communications and possibly even nuclear propulsion and weapons secrets to the other nation.
This cannot be achieved overnight.
Now, don't get me wrong.
If you ask the two navies to do this they will achieve it.
The military are good at making things work.
There will be a test patrol and it will be declared a success.
But then the budgets tighten and what starts as a once in a while event will gradually become the norm.
Each nation will by then have halved its nuclear weapon footprint.
So even if times get better and we can once again afford to go it alone where would be the justification for increasing it? What would we say to the world? We would either have to stay with the joint programme or settle for a much reduced deterrent programme not due to cost but due to politics.
A joint programme could end up as a bit of a one way street.
But the elephant in the room for me is the US.
They don't seem to have objected.
They need the UK to buy a new system (from them).
We could end up buying a French one if we go ahead with joint patrols.
Also, the UK/US programme goes right back.
We share the same language and use similar kit.
Why did we not approach the US on this basis? And, if we did, why did they refuse? Then of course there's the famous 'Letter of Last Resort' that sits inside a safe within a safe in the bowels of the UK nuclear deterrent submarine to consider.
A letter written and signed by the Prime Minister, sealed in an envelope only to be opened if the UK has been hit by a pre-emptive nuclear attack and the PM and designated deputy are dead.
The letter the contents of which are only known to the PM, tell the submarine captain what to do in that event.