A FAMOUS protest where 70,000 football fans flashed red cards at Margaret Thatcher would have faced being “criminalised” under new legislation, MSPs have been told.

The former Tory Prime Minister was guest of honour at the 1988 Scottish Cup Final between Celtic and Dundee Utd, amid heightened political tensions over the poll tax.

But Labour MSP James Kelly said an eye-catching demonstration – where supporters brandished red cards as Mrs Thatcher took her seat at Hampden – could have been outlawed under the Offensive Behaviour at Football and Threatening Communications Act.

Mr Kelly has submitted a Member's Bill to Holyrood in a bid to repeal the legislation, which he described as being "discredited" and ineffective.

He told Holyrood’s justice committee: “There should be freedom of expression. For example, at the 1988 Scottish Cup Final, I took part in a political demonstration against the Conservative Prime Minister, Margaret Thatcher, who was presenting the trophy that day.

“There was a red card display. That’s a legitimate act of political expression within a football ground.

“Some might argue that those kind of acts might be criminalised under this legislation.”

The Offensive Behaviour at Football Act – which came into force in 2012 – criminalises behaviour which is ''threatening, hateful or otherwise offensive at a regulated football match including offensive singing or chanting''.

Mr Kelly insisted there had been a “dramatic improvement” in crowd behaviour at football in the 40 years he had been attending matches.

But he added there was now “more friction” between police and fans, with a need to rebuild trust if the new law is scrapped.

He said fans could not understand why they were being targeted by legislation, adding: “For example, over the period that T in the Park was in the place, there were 3600 incidents, including some serious incidents of sexual assault and attempted murder.

“But there’s not any specific legislation targeted at concert-goers.

“So when football fans see that, they question the validity of what is being put across here.”

Asked by SNP MSP George Adam if he thought it was correct for songs celebrating terrorism to be sung at football matches, Mr Kelly said “hateful” behaviour was “totally unacceptable”.

But he added: “I have to say to you, Mr Adam, in advancing that point of view you do so with some lack of credibility.

“In 2015, you signed a motion tabled in this parliament by [former Justice Secretary] Kenny MacAskill, celebrating the Easter Rising.

“If you went along to a football ground and you took part in songs commemorating the Easter Rising, you might find yourself spending some time in a police cell.”

Mr Adam previously branded Mr Kelly “utterly irresponsible in seeking to erode the powers our police currently have to tackle bigotry”.

He said there had been a “steady, systematic worsening of behaviour at games both on the field and off the field”, which took a more sinister turn in the aftermath of a notorious Old Firm match in 2011.

Celtic manager Neil Lennon was sent bullets and a parcel bomb in the post following the ill-tempered game, with two other high-profile Celtic fans – the late Paul McBride QC and former Holyrood deputy presiding officer Trish Godman – also sent what police described as "viable explosive devices".

But giving evidence to the justice committee, which is considering his repeal bid, Mr Kelly accused the SNP of a “complete overreaction” and rushing through legislation “against the will of all the opposition parties”.

He said the bad behaviour of fans was “much more serious going back to the 70s and 80s”.

He added: “I have been a football supporter for over 40 years. I attended my first football match in 1969.

“I can well remember a time, particularly around the late 70s and early 80s, when there was a lot of public disorder at football matches, where there was singing of offensive songs by both sets of supporters going along to games, where there were clashes inside the ground and also outside the ground and there was a tense atmosphere around the football.”