The Conservative MP Daniel Kawczynski has received a formal warning for attending a conference with notorious far-right political figures.

The Shrewsbury and Atcham MP apologised for attending a conference alongside nationalist leaders in Rome earlier this week after party bosses branded his behaviour unacceptable.

He had previously argued that the Hungarian prime minister, Viktor Orbán, and Matteo Salvini, the leader of Italy’s far-right League, who had also been scheduled to speak at the event, “represent serious ideas and concerns, some of which are shared by many citizens of the UK”.

In a blog on the Spectator website, Kawczynski criticised the Guardian for breaking the story about his involvement in the conference.

He wrote: “The paper has suggested a Tory MP should not speak at an event ‘with far-right’ figures on the subject of nationalism. But they are wrong … Orban and Salvini are not to everyone’s tastes, of course. And I don’t agree with each and every one of their policies … [but] they represent serious ideas and concerns, some of which are shared by people in Britain.

“Clearly, offence archeologists have done a thorough job in finding historic remarks from some of the participants that jar with the liberal world-view.”

On Thursday, the Conservative party confirmed in a statement that it had issued the backbench MP with a formal warning for attending the event. “Daniel Kawczynski has been formally warned that his attendance at this event was not acceptable, particularly in light of the views of some of those in attendance, which we utterly condemn, and that he is expected to hold himself to higher standards,” a spokesperson said.

“Daniel has accepted this and apologised.”

Orban has been Hungary’s prime minister since 2010, and has been accused of promoting antisemitic conspiracy theories and far-right tropes. Other speakers at the conference included Italian leaders closely associated with Benito Mussolini’s fascism and a far-right member of the Le Pen family.

Kawczynski’s decision to attend was criticised by Muslim and Jewish groups. Marie van der Zyl, the president of the Board of Deputies of British Jews, said the party ran the “serious risk of the public assuming that they share his views” unless they disciplined him.

“Mr Kawczynski’s defence, that ‘it is only common sense to talk with parties and politicians that are either leading their respective countries, or will perhaps take power in the next few years’, is a specious one, for the simple reason that the MP for Shrewsbury and Atcham is not any sort of government representative,” she said.

In Rome on Tuesday, Orbán closed the National Conservatism conference with a debate championing national sovereignty.

Salvini sent his apologies for not attending the event after suffering an embarrassing defeat in regional elections. Giorgia Meloni, whose Brothers of Italy party is supported by members of Mussolini’s family, gave a speech on Monday in which she defended “national identity”.