Thank you very much for clarifying. Many people are keen on suing for defamation without having full appreciation of the law or practicalities of doing so. I will try and clarify the position below to give you a better understanding and cover some of these practicalities.
First of all, certain conditions must be met for the statement to be classified as defamatory. These are:
1. There has to be a defamatory statement - the assessment that is often used to establish this is whether the statement tends to lower the claimant in the estimation of right-thinking members of society generally
2. Its publication has caused or is likely to cause serious harm to the reputation of the claimant – this will vary based on what effect it will have but it really has to be something sufficiently serious
3. The statement has been published by the defendant to a third party
4. The claimant must prove that the words complained of were published about them - this should not be an issue if the claimant is named or clearly identified.
Whilst it may be easy to prove that defamation has taken place, the legal process of pursuing such a claim is often complex and prohibitively expensive. A claim must be made in the High Court and will likely require the help of professional defamation lawyers, so the costs will often be high right from the outset, usually in the thousands. There is also no legal aid available for such claims so the complainant must fund these personally.
Also, you have to appreciate that speaking the truth cannot be defamation as that is only possible with false or misleading statements.
Overall, I think it is very unlikely that an actual legal claim for defamation will be made and this is more likely a treat to make you remove the comments or issue an apology.