Senior government officials knew weeks ago that the Southport ‘attacker’ could face terrorism charges

Downing Street denied the government was involved in the timing of the toll announcement. A spokesman said: “No – the decision on charging and when it is made rests with the CPS.”

Ms Cooper warned against speculation about the case, adding: “The most important thing is to get justice for Baby, Alice and Elsie and their heartbroken families and everyone affected by the attack and no one should be put at risk.”

Jonathan Hall QC, an independent researcher on counter-terrorism law, said authorities needed to be more open about information in terrorism cases to avoid an “information gap” that could be exploited by people on social media.

Mr Hall told BBC Radio 4’s Today programme: “The police and the CPS are operationally independent and that is important. And if the police and the CPS are saying “we really don’t think you can post any more in the public domain” I think that should influence the government.

“On the other hand, I also think that the government needs to realize and will realize that if there is an information gap, especially in the mainstream media, then there are other voices, particularly in social media, that will try and fill it.

“I would always say to the government … if there’s information you can provide, put it out in the open and be very careful not to fall into the trap of saying, ‘We can only say snot because there’s a criminal investigation.’

“Quite often there is enough information that can be released and I think I see the police trying to do that. Now they understand that just saying, ‘there are allegations, we can’t say anything more’ is not going to help today.”