Jo Cox’s bereaved husband says mainstream politicians are legitimising extremist anti-immigrant views

Mainstream politicians are legitimising extremist anti-immigrant views by “aping” far-right rhetoric, the bereaved husband of killed MP Jo Cox has said.

Ms Cox was stabbed and shot to death outside her constituency surgery in West Yorkshire on Thursday by a man eyewitnesses said shouted “Britain first”.

Investigations suggest that the man arrested by police over her death, Thomas Mair, appears to have had links to white supremacist and far-right groups.

Brendan Cox wrote a paper on the subject of anti-immigration sentiment a few weeks before his wife’s death and has circulated it after her killing.

He argued that mainstream politicians had reinforced the frame of right-wing populists on immigration and had been “fanning the flames of resentment”.

“Petrified by the rise of the populists they try to neuter them by taking their ground and aping their rhetoric,” he said.

“Far from closing down the debates, these steps legitimise their views, reinforce their frames and pull the debate further to the extremes (Sarkozy and the continuing rise of Front National is a case in point).”

He added: “They obsess over numbers (to most people 10,000 sounds as scary as 100,000), when they should focus on reinforcing frames of fairness and order.

“The UK government policy is a masterclass in how to get the crisis wrong; set an unrealistic target, miss it, report on it quarterly and in doing so show a complete lack of control heightening concern and fanning the flames of resentment.”

David Cameron was criticised last year for describing refugees coming from Syria to Europe as a “swarm”, using rhetoric critics said was dehumanising.

Labour too attracted ire at the last general election for putting the campaign slogan “controls on immigration” on a mug.

Ukip's leader Nigel Farage has gone further and spoken on television of immigrants and refugees as carriers of infectious diseases like HIV.

The campaign to leave the European Union has also focused with laser-like intensity on immigration and immigrants in recent weeks. On the day of Ms Cox’s killing Ukip leader Nigel Farage unveiled a poster featuring refugees that was likened by many onf social media to “Nazi propaganda”.

After Ms Cox’s killing Mr Cox said: “[Jo] would have wanted two things above all else to happen now, one that our precious children are bathed in love and two, that we all unite to fight against the hatred that killed her. Hate doesn't have a creed, race or religion, it is poisonous.”