Curiously, French President Emmanuel Macron closed his country's border with the UK for 48 hours. Why 48 hours?

If the closure was meant to keep the British coronavirus variant out of France, then surely he should have closed the Calais port to British traffic for longer - at least until after the mutated strain is found to be no more deadly than the regular variety.

A Daily Express poll showed 95 percent of its readers believed Macron, in fact, closed the border to try and force the UK into a Brexit deal of his choice.

It is impossible to verify such a conspiracy theory - but it is gaining traction among the Brits.

Macron may be spared such accusations if the lorry ban was totally down to the coronavirus variant that German laboratory BioNTech says its vaccine is expected to be effective against.

But if he was trying to take advantage of the sudden virus development to give his UK counterpart Boris Johnson a sharp lesson on what a no-deal Brexit could mean, the French president would be playing a dangerous game.

He may think that a 48-hour closure would be long enough to create enough chaos to persuade the Brits that it is not worth endangering a Brexit deal for a dispute over fish.

He could be betting that empty supermarket shelves would press Johnson to accept his demand for greater access to British fishing grounds.

But such a move to politically charge a pandemic in order to drain the last drop of goodwill that has kept the negotiations afloat could well backfire.

It is hoped that the 48-hour border closure had nothing to do with the Brexit talks.

As I said in this column some time back, of the three stumbling blocks, Johnson is believed to be more concerned about the issue on state aid to industries.

The current protocol, if written into the deal, would prohibit government subsidies to industries - including incentives to stimulate post-pandemic recovery.

However, the European Union as a whole will still be able to provide such incentives, even though individual member states will not be permitted to act of their own volition.

Johnson knows that fisheries is a red line for Macron - and also the French president's Achilles' heel that he can explore to press the EU to give the UK greater flexibility on the subject of state aid that is expected to be central to he British prime minister's economic recovery plan.

Hasn't 10 Downing Street already identified green energy as the way to go? That ambition will be inhibited if the British government cannot get rid of the state-aid leash.

In these final hours of negotiations, plenty of speculation has been thrown up. It did not surprise me when the British media reported that Johnson may be willing to offer a concession on fishing in exchange for a EU concession on state aid.

As the clock continued to tick, the Financial Times broke the news that Johnson and European Commission president Ursula von der Leyen had been in secret talks.

There's a sense of deja vu here. High level engagement and secrecy are the hallmarks of EU negotiations - suggesting both sides are now in the "tunnel" to cut a deal.

Hard Brexit rehearsal at play