Tesco failed to contact three people it is suing for libel to seek an apology, despite claims by the supermarket that all it wants is a retraction.

Sir Terry Leahy, the supermarket's chief executive, wrote a letter to The Times, stating that his company tried “time and time again” to engage with its critics in Thailand and to use force of argument to show that it has not been aggressive in its expansion.

He spoke out after a group of prominent British authors accused Tesco of using “deeply chilling” tactics to silence its critics, including its use of Thai criminal libel law, which carries a two-year prison sentence and a fine of £16.6 million.

The company also issued a statement saying that it had a “fervent wish” to reach agreement with Jit Siratranont, a former Thai MP, and two journalists, but “despite numerous attempts to get them to set the record straight, this has not happened”.

But Tesco now admits that it did not speak directly to either of the journalists and contacted Mr Jit only through “media statements, interviews and third parties”.

Mr Jit and the two journalists told The Times that they had received no request for an apology.

Mr Jit, who is vice-general secretary of the Thai Chamber of Commerce, is being prosecuted under criminal law for a speech in which he accused Tesco of expanding rapidly at the expense of small local retailers. “I confirm that I didn't receive a request for an apology either before or after I received Tesco's writ,” he said. “I criticised [them] with evidence and [in good faith]. If Tesco doesn't agree they must explain to me politely, but they don't.”

Kamol Kamoltrakul, a freelance journalist, is being sued in a civil action for £1.6 million after he wrote a column for Bangkok Business News stating that supermarkets such as Tesco Lotus, the company's Thai operation, were driving “mom and pop stores” out of business. He said: “I stand for my honesty and will prove it in court.” Mr Kamol and Mr Jit admit to making a factual error, but stand by the thrust of their thesis.

Nongnat Hanwilai, a staff columnist for Bangkok Business News, said that she was not aware of any attempt by the company to seek an apology for her comment that “Tesco Lotus doesn't love Thais”. She is also unaware of any contact between the supermarket and the newspaper.

A Tesco spokesman said that Tesco Lotus “met with representatives of Mr Kamol and Nongnat Hanwilai in the form of the management of the Nation Group, the newspaper group in which they published their false allegations, on two occasions shortly before the writs were served and on several occasions afterwards”.

Ms Nongnat said that even if Nation Group had been contacted by Tesco, it “never interferes with [articles] as long as they are in accordance with constitutional rights and ethical standards”. She stood by her article, she said. “To apologise is to admit guilt,” she said. “I still firmly believe that I only did my professional job in airing criticism against Tesco's fast expansion in Thailand.”

Sir Terry declined to comment further, but a spokesman for his company said that Tesco Lotus's legal action was a final resort. “There is no question that all of the individuals were very well aware of the seriousness of the allegations and the likelihood of action if they did not stop making them and apologise. Tesco Lotus remains open to any approach from the individuals concerned with a view to setting the record straight in public, and would still greatly prefer this to court action.”

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