The former leader of Ukip in Rotherham has been ordered to pay £80,000 in damages to two local Labour MPs for falsely alleging that they knew about the city’s child sexual exploitation scandal but failed to act.

Speaking to Sky News in January last year, Caven Vines, the former leader of Ukip on Rotherham council, claimed that the MP for Wentworth and Dearne, John Healey, and the MP for Rother Valley, Sir Kevin Barron, “knew what was going on”.

A ruling from the high court deemed Vines’s comments to have been defamatory and Mr Justice Warby awarded Barron and Healey £40,000 each in damages on Wednesday. He said the ruling “strikes an appropriate balance between the need to vindicate the claimants’ reputation and compensate them fairly for the harm done, and the need to avoid overchilling freedom of speech in the political arena”.

The judge also ruled that Vines should pay the MPs’ legal costs for the 18-month libel action, ordering him to pay £30,000 of this upfront within 28 days.

In a statement, Healey and Barron said they were very pleased with the full vindication that the judgment gave them. “After 18 months we’re relieved at last this fight to defend our reputation is over,” they said.

“Caven Vines’s lies have been allowed to run for too long, but today the high court has ruled comprehensively against him. Legal action should never have been needed but he has refused to apologise or admit his allegations against us on Sky News were totally untrue, so he left us with no other option than to force him to face up to the truth and to clear our name.

“Now we look forward to securing a similar judgment in the linked case against Jane Collins MEP, who is trying to hide from British justice by claiming protection of the European parliament. She may delay but she cannot stop the British courts from catching up with her.”

From left: John Healey, Sarah Champion and Sir Kevin Barron. Photograph: PA

The two MPs, along with the MP for Rotherham, Sarah Champion, are taking legal action against the Ukip MEP for Yorkshire and the Humber, Jane Collins, for libel and slander after she made similar accusations that local MPs “knew many of the details of what was happening”.

Collins made the comments in a speech at her party’s conference in September 2014. She has since attempted to claim immunity from the charges because of her status as an MEP.

Lawyers for Healey and Barron said they had not pursued the case for money – it was about establishing the truth. Speaking in court last month, Gavin Millar QC said: “We know Mr Vines is not a wealthy man and this is not about getting money. The claimants have made clear their reasons for pursuing this case doggedly.

“He still wants to maintain the truth of the very, very grave allegation he made and the only way, in the teeth of an opinion like that, they can get vindication in the public arena is to pursue this. Mr Vines has never still said, even today, that there is no evidence whatsoever in his possession to support that allegation.”

Vines, who lost his seat on the council in the recent local government elections, told the court he had meant that the MPs had known about the scandal “like everybody else in Rotherham” after media reports in 2012.

After an investigation in the Times newspaper, which alleged that gang rape and trafficking was widespread in the city, a report by Prof Alexis Jay, a former chief inspector of social work, concluded that failures of political and police leadership contributed to the sexual exploitation of 1,400 children by Asian men in the town over a 16-year period.

Jay’s investigation, which concluded in 2014, found that Rotherham council knew as far back as 2005 of sexual exploitation being committed on a wide scale but failed to act.