Editorial: ​By-elections are unpredictable ... Nigel Farage's resignation move involves some peril for the Reform UK leader

​Nigel Farage has resigned his House of Commons seat to stand again in a by-election.

​The Reform UK leader plans to use re-election as Clacton MP as a mandate for his politics and leadership.

The constituency has been through this before. The one-time Tory politician Douglas Carswell quit as MP for Clacton after defecting to Mr Farage's then Ukip party in 2014, and easily won re-election in the by-election he caused. Mark Reckless, a Tory MP, did similar in a Kent constituency in 2014, winning re-election for Ukip. But both men later lost out - the former fell out with Mr Farage and the latter lost his seat back to the Conservatives in the 2015 general election.

This is a perilous manoeuvre for Mr Farage. By-elections are unpredictable yet Andy Burnham risked such a contest recently and won handsomely. But there is no escaping the context of Mr Farage's dramatic announcement yesterday - he accepted an astonishing £5 million gift from a wealthy benefactor for, he claims, his security. It is hard to think of any equivalent personal donation to a British political leader in recent decades.

The UK simply does not have the large scale cash corruption that other nations do, above all badly run, third world societies.

While Mr Farage is a remarkable political talent who has, like his even more flawed friend Donald Trump, single-handedly changed the political debate on crucial matters of public interest such as immigration and the EU, it is highly regrettable that, similar to the US president, he has sullied that record in dodgy financial dealings.

Meanwhile, there is an onus on the state to protect outspoken politicians who have a mandate. Northern Ireland politicians were murdered by the IRA. No such leader at risk should have to fund their own security.