Why has Labour’s leadership election descended into a row about dirty tricks?

For the most part, Labour’s leadership contest has avoided personal attacks. The candidates have been criticised by some commentators for pulling their punches on Jeremy Corbyn, even though he led the party to its worst defeat since 1935.

However, the gloves came off yesterday. Labour Party headquarters has reported the campaign of the frontrunner Sir Keir Starmer to the Information Commissioner for an alleged breach of data protection rules. Two members of Sir Keir’s team are said to have “scraped” (hacked into) Labour’s 500,000-plus membership list.

His team dismissed this as “utter nonsense”. It claimed the staffers clicked on a link in an email sent out by a rival candidate, and found it could access the party’s list. Sir Keir’s campaign then alerted Labour HQ, whose response was to refer the campaign to the commissioner.

It emerged last week that Rebecca Long-Bailey’s campaign circulated links to volunteers capable of allowing them access to Labour phone banks. Her campaign said it acted innocently. Previously, The Independent revealed that Ms Long-Bailey was let off by Labour HQ after breaching a ban on promoting campaigns to members using party data.

The list of members is regarded as the “crown jewels” because Mr Corbyn’s successor will be chosen by them in a “one person, one vote” ballot. Although candidates with enough nominations by 14 February to make the final shortlist will be able to use the list at a cost of £5,000, earlier access would enable them to canvass for support before then. Ms Long-Bailey is believed to have been helped by data held by the pro-Corbyn grassroots group Momentum and the Unite union, who are both backing her leadership bid.

Officially, Labour HQ is neutral in the leadership campaign. But many of its staff are fiercely loyal to Mr Corbyn. While he has not endorsed anyone, he has described Ms Long-Bailey as “our candidate”. She denies being “continuity Corbyn.“

The leaking of the complaint against Sir Keir is seen by his allies as “dirty tricks” designed to undermine his campaign, which received a boost on Friday when members in Mr Corbyn’s Islington North constituency party supported Sir Keir. Labour officials insist they had a statutory duty to pass the information about his team to the commissioner. With the new leader not announced until 4 April, to loosely paraphrase Tony Blair, things can only get bitter.