Arron Banks, the chairman of Leave.EU, has taken the unusual step of writing to each household in my parliamentary constituency of Folkestone and Hythe, telling them that I am a “disgrace” and a “snake in the grass”. He claims that “I have never respected the result of the [Brexit] referendum.” However, he is unable to point to anything in my voting record in parliament to substantiate his assertion.

This letter has certainly provoked a strong response. One constituent has contacted me saying it is, “the most despicable piece of slander and defamation I have seen”. Another wrote calling his letter, “a libellous and ridiculous attack on your character as a member of parliament. Regardless of our political persuasions, I utterly deplore such bully-boy tactics and reject his garbled nonsense.”

It is clear that Banks’s main complaint against me is that I, and the other members of the digital, culture, media and sport select committee that I chair, have called on him to give evidence to our inquiry into disinformation and fake news. He is angry that we asked him about his links to Russia, secret meetings with that country’s ambassador, connections to Cambridge Analytica, and where he found the funds to become the biggest donor in British political history, when so many of his businesses seem to lose money. Like so many would-be bullies, Banks likes to have a go at other people, but hates being questioned about his own affairs.

As an MP and chair of a select committee, it’s my responsibility to make sure we pursue our inquiries without fear or favour. Banks’s strategy is one of intimidation, and when asked recently whether by sending these letters he was trying to put the frighteners on MPs, he said, “there is an element of that.” Well no matter how many letters he writes, I won’t be stopped by him from doing my job.

Banks also complained that in the summer I “shared a platform … with Guardian journalists.” This is true: I spoke at the Byline festival in August with the Orwell prize-winning journalist Carole Cadwalladr – someone who receives abusive messages on social media from Banks and his cronies. Cadwalladr and I were both invited to speak about our respective investigations into disinformation, including the role of Russia in promoting it, and social media in allowing it to spread. Banks hates us talking about this. For those of you who aren’t familiar with the Byline festival, it is an independent summer event that promotes free speech and independent journalism: Banks hates Byline as well.

In criticising me for the platforms I’ve spoken on, Banks seems to be suggesting that we should only speak to people who share all our political opinions. Such an approach reduces politics to mere silos where people shut themselves off from other people, opinions and ideas. I can’t think of anything that would be more damaging to our democracy at this time. The issue of state-sponsored disinformation, organised from countries like Russia and Iran, is a major challenge, and we need to work together to confront that threat, and make the social media companies do more to act against the known sources of these campaigns.

The unelected Banks is now displaying a consistent pattern of behaviour where he constantly seeks to abuse and intimidate politicians and journalists – and he is not the only one. This is partly just attention seeking, but it also has a more sinister edge. Unchecked, this is the kind of behaviour that allows the virus of fascism to seep into democracy.

• Damian Collins is Conservative MP for Folkestone and Hythe and chair of the Commons digital, culture, media and sport committee