When he stepped out of the Palace of Westminster on Thursday and declared no confidence in the prime minister, there was a clear sense Jacob Rees-Mogg was firing the pistol on what would be an immediate challenge to Theresa May.

He is after all the chair of the European Research Group - a wing of the Conservative Party thought to have at least 80 members who have made no secret of their desire for a much harder Brexit than the one Mrs May is negotiating.

If the ERG was as organised and dangerous as had been assumed, this was to be a key moment - the mood in Westminster changed immediately, with many journalists anticipating an announcement later that afternoon.

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But as things stand, just over 24 hours later, the number of Conservative MPs now publicly calling for a confidence vote remains at around 20.

There has been silence from Sir Graham Brady, chair of the 1922 Committee of backbench Conservative MPs responsible for counting the letters and declaring when the threshold of 48 has been crossed.


For now, we can only assume the total number of letters required has not been received.

That said, it has made Number 10 nervous.

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Sky News understands all government whips have been ordered back to Westminster from their constituencies, presumably in anticipation the threshold will be crossed at some point.

But no matter what spin is put on this by Mr Rees-Mogg or his fellow ERG organisers like former Brexit minister Steve Baker, this apparent lull in activity and pressure was not in the script.

Pulling the trigger was a major decision - the ERG cannot afford to fire blanks if they are to maintain their influence.

Image: Steve Baker thinks Mrs May will face a confidence vote

For months the group have been toying with the idea of submitting their letters of no confidence as a bloc.

Publicly, their reasons for not doing so has been that they wanted to urge the prime minister to change her policy, rather than force a change of the prime minister.

Privately there was an understanding that a leadership challenge at this stage in the Brexit process could be seen as self-indulgent by the public and pointless in practice - given a new leader will still be faced with the same parliamentary arithmetic and lack of majority that has so hobbled Mrs May.

Yesterday, Mr Rees-Mogg made clear that calculation had changed. What is far from clear is whether all of his ERG colleagues agree.

Dominic Raab, who was until yesterday the Brexit secretary but who has also in the past been an ERG member, made clear he wanted Mrs May to continue.

Other prominent Eurosceptics from the ERG have also remained silent on whether or not they have or will submit a letter - Iain Duncan Smith, John Redwood, Sir Bernard Jenkin and Sir Bill Cash to name a few.

And if they have reservations, then it would be fair to assume the more moderate middle of the party are aghast.

One backbencher, who told me they may well vote against the Brexit divorce deal Mrs May has struck with the EU, nonetheless said they stood behind her leadership, describing efforts to seek a confidence vote as "ridiculous".

"The struggle to get to 48 shows the ERG are not as strong as people perceive", said the MP.

So what does this mean for Mrs May?

There is a sense in Number 10 that the 48 letter threshold will probably be reached, but the fact that it has not been yet - despite a major intervention by the ERG - is being seen as a sign there are still grounds to fight on.

Combine that with the decisions of leading Brexiteers Michael Gove, Liam Fox, Penny Mordaunt, Andrea Leadsom and Chris Grayling to stay in cabinet, and the prime minister might just feel she can ride out the bloody upheaval of the last 48 hours

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Of course, there will undoubtedly be Conservative MPs who choose not to submit a letter, but who would not back the prime minister if a confidence vote were to take place.

And there are those who argue that if a rebellion against her were to number more than 100, she would have no option but to stand down.

But the rules say more than 50% of the party would need to vote against her to force Mrs May to stand down.

She insists she will fight any challenge. Her aides insist she will take a victory even if it is by a single vote.

The fact the challenge of Mr Rees-Mogg failed to bring about an immediate challenge will likely only stiffen her resolve.