LONDON (TIP): Brexit campaigners accused the government of trying to rig the EU referendum and threatened legal action on June 9 as former London mayor Boris Johnson squared up for the campaign’s first TV debate.

British MPs prepared to approve emergency legislation to extend voter registration — a move that has infuriated the “Leave” camp because many late requests have been from broadly pro-EU younger voters.

Arron Banks, co-chairman of the Leave. EU campaign, said it was “a clear attempt to rig the referendum or, at a bare minimum, to load the dice”.

“It’s a desperate attempt by the establishment to register as many likely Remain voters as possible.

“We are therefore considering all available legal options with our legal team,” he said.

The outrage was sparked by a glitch with the government’s main registration website just ahead of a previous deadline of midnight on Tuesday, playing into a heated debate ahead of a knife-edge vote.

The deadline is now being extended until midnight.

Education minister and “Remain” supporter Nicky Morgan, said the “Leave” camp was “turning into a bunch of conspiracy theorists”.

Around 132,000 of the 525,000 people who did successfully register on Tuesday were aged under 25, compared to around 13,000 from the 65-to-74 age group.

The “Remain” camp got another boost when Conservative MP Sarah Wollaston announced she was switching sides from the “Leave” camp, telling the BBC late Wednesday she was “uncomfortable” about the credibility of their claims about the cost of EU membership.

Former Conservative prime minister John Major and his erstwhile political rival in the 1990s Tony Blair — were also set to put party politics to one side later on Thursday for a pro-EU rally in Northern Ireland.

They were expected to warn that “Brexit” could “jeopardise the unity” of the UK, lead to another referendum of Scotland‘s future and threaten Northern Ireland’s hard-won truce.

“Although today Northern Ireland is more stable and more prosperous than ever, that stability is poised on carefully constructed foundations,” Blair was to say. “We are naturally concerned at the prospect of anything that could put those foundations at risk.”

Scotland’s governing secessionist Scottish National Party has said Britain voting to leave the EU, while a majority of Scots voted to stay in, would trigger a second referendum on independence.

In Northern Ireland, the Good Friday agreement signed by Blair in 1998 put an end to three decades of mostly sectarian conflict in which some 3,500 people were killed.

Meanwhile, in a boost for “Leave”, leading businessman Anthony Bamford, chairman of construction machinery firm JCB, came out in support of Brexit, telling his 6,000 employees in a letter they had “very little to fear” from leaving the union.

“JCB will continue to trade with Europe, irrespective of whether we remain in or leave the UK,” he wrote. “I am very confident we can stand on our own two feet.”

Former London mayor and leading “Leave” campaigner Boris Johnson will go head-to-head with Scotland First Minister and “Remain” supporter Nicola Sturgeon for a potentially fractious debate later on Thursday.

The surge in voter registration requests on Tuesday came immediately after a tense TV face-off between Prime Minister David Cameron and anti-EU leader Nigel Farage .

Cameron fended off hostile questions about high immigration rates of EU workers while Farage was forced to defend himself against charges of racism.

The WhatUKThinks website’s average of the last six domestic opinion polls puts the “Remain” camp on 51 percent and the “Leave” campaign on 49 percent, but bookmakers still have “Remain” as strong favourite.

(AFP)