PM’s message to sit up and pay attention

Boris Johnson has gone far with the help of simple three word slogans.

Tonight, as the country is again in the grip of a fast spreading virus variant, and he is in the grip of a political mess, there's a new one, "Get Boosted Now".

The prime minister's language was dramatic, warning people that the pandemic is again an 'emergency' with a 'tidal wave' now coming of the omicron variant.

He called on you to have that booster dose as soon as humanly possible or, if not, the NHS could be overwhelmed by a terrible new wave of the pandemic.

The booster is the defence against what's coming, his argument. The responsibility therefore on all of us to come forward for another dose of the jab.

The practicalities he promised sound like a huge expansion of the scheme. Instead of all over 18s in England being offered a booster by the end of January, the new target is that they'll be offered one by the end of this year.

There'll be 42 'new military planning teams' across every region. New mobile vaccination units, bigger sites, expanded hours for centres that are already in operation.

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A new, what the prime minister described, "Omicron emergency booster national mission".

He's promised extra cash for Wales, Scotland and Northern Ireland, too.

There is no doubt that to deliver a speech in this manner, any prime minister, alone at the polished table in the grandeur of Downing Street, sends a massive message to the public to sit up and pay attention.

The so-called 'national address' is a lever that Number 10 is only meant to pull in extraordinary moments.

Government insiders argue that the spread of Omicron is so much faster than expected that to wait any longer before making such an appeal, not to shout about the risk from the rooftops would be a mistake.

Many members of the public may be worried enough to take action, to rush to book their booster if they have not yet had it, or even to come forward for their vaccination which they have turned down so far.

Yet Mr Johnson's stern words tonight may run into three different challenges.

It won't be easy to expand the booster programme at such a pace. There's been plenty of anecdotal evidence about the availability and eligibility, and questions about why it didn't get going much more quickly, weeks ago.

Second, Mr Johnson's credibility has taken a significant knock in recent weeks. Will the public, this time, be as willing to listen to him?

And in his own party there is frustration at his decision making and scepticism about what's going on. The prime minister can make bold and urgent promises about the booster, but keeping them is something else.