A relative of a victim of the Birmingham pub bombings has said that the decision not to bring charges following a re-investigation is “ethical, moral and legal turpitude”.

Julie Hambleton’s eldest sister Maxine was one of 21 victims of the attacks in November 1974, which remains the worst unsolved terrorist atrocity committed on the British mainland.

The attacks had been re-investigated by West Midlands Police, but the Crown Prosecution Service said on Monday that there was insufficient evidence to bring charges.

Ms Hambleton, 60, has now said that the decision shows that prosecuting people over the Troubles is “off-limits” and is tantamount to a “cover-up”.

In all honesty, we weren't surprised, but we're disappointed, as we've been disappointed for the last 49 years

She said: “In all honesty, we weren’t surprised, but we’re disappointed, as we’ve been disappointed for the last 49 years.

“That’s all that the authorities have ever done – disappointed us.

“We pay these people to be in positions of allegedly protecting and serving and representing us, and it’s actually the very antithesis of what they do.

“So the CPS’ decision is a continuation of the myth and rumour that is attached to the murder of our loved ones.

“You’ve got Lucy Letby, who killed those poor little babies.

“She’s been given multiple life sentences, quite rightly, yet in the same breath and in contrast to that, this Government are pushing to implement legislation that will give the murderers of our loved ones total immunity.

“People were blown up in cold blood, 200 people were left with life-changing injuries, and this Government wants to implement a bill that will give every single murderer during the Troubles in Northern Ireland, England and Ireland, total immunity.

“It’s just sheer madness.

“How is it possible to differentiate between one murder and another? Murder is murder.

“The Government is creating a hierarchy of victims where some families it appears are more entitled to justice than others.

“This is tantamount to ethical, moral and legal turpitude.”

Twin blasts destroyed the Tavern in the Town and Mulberry Bush pubs on November 21, 1974, with a third bomb failing to detonate.

Six Irishmen, Hugh Callaghan, Paddy Hill, Gerry Hunter, John Walker, Richard McIlkenny and Billy Power, were wrongly convicted over the attacks and jailed for life in 1975, but were freed in 1991 after the Court of Appeal ruled their convictions were unsafe.

The CPS said on Monday that after a “thorough and careful” review of new evidence given to it by West Midlands Police, there remained insufficient evidence to positively identify who planted the bombs.

It said it would continue to work with police if new lines of inquiry emerged.

The families of the victims have long called for a public inquiry into the attacks, a call that was repeated after a similar inquiry was announced earlier this year into the 1998 Omagh bombing.

Ms Hambleton, who leads the Justice4the21 campaign group, said she believed there was a sustained effort to deflect blame from those involved in investigating the attack.

She said: “You’ve got Grenfell, the Manchester arena bombing, Hillsborough and many, many more public inquiries that have taken place.

“Some of them will have been hard fought for, but some they only have to wait 12 or 18 months.

“We stand with each of them shoulder to shoulder, but where is our public inquiry?

This is no more and no less than political policing and political justice - anything to do with Northern Ireland and the politics seems to be off-limits to ever be investigated, especially anything to do with Republican violence

“This is no more and no less than political policing and political justice – anything to do with Northern Ireland and the politics seems to be off-limits to ever be investigated, especially anything to do with Republican violence.

“Our case could not make this point more profoundly. It’s just one huge, massive cover-up.”

Next year marks the 50th anniversary of the attack, and there are plans to commemorate those who died this year and in 2024.

But Ms Hambleton said no front-bench MP or member of the royal family had ever attended a memorial event, and previous requests to politicians had been rejected.

She also voiced concerns over the new Northern Ireland Troubles (Legacy and Reconciliation) Bill, which would give immunity from prosecution for Troubles-related offences to people who co-operated with a new information retrieval body.

It would also prevent future civil cases and inquests into Troubles offences.

The Bill has provoked widespread opposition, with the King being urged to refuse Royal Assent earlier this month.

She said: “This Bill is, according to this Government, a means to stop any future vexatious claims against soldiers.

“But this couldn’t be further from the truth, because the Bill is purely a mechanism for the security services, for successive governments, to quite literally bury their dirty, toxic past of collusion and complicity with Republican and loyalist terrorists during the time known as the Troubles.

“This Government believes that this Bill is the best way for families like ours and thousands of others to move on.

“Such arrogance and hubris by them is absolutely contemptible.

“Who are they to tell us how we should or shouldn’t move on?

“Victims’ families in Northern Ireland and England are united in opposing this bill.

“People are being blindsided by the Government into introducing a bill that will set a precedent for future generations to come.”