Up to 800,000 jobs across the UK could be axed if Britain broke away from the EU, George Osborne has warned. The chancellor, speaking at home improvement store B&Q, claimed a 'Leave' vote at the 23 June referendum would almost immediately trigger a year-long "DIY recession".

"It's only been eight years since Britain entered the deepest recession since our country had seen since the Second World War," Osborne said.

"Every part of country suffered and the British people have worked so hard to get our country back on track. Do we want to throw it all away? Can we knowingly vote for a recession? Does Britain really want this DIY recession?"

The chancellor's speech coincided with the release of the Treasury's analysis into the immediate economic impact of a split from Brussels. The department looked at two scenarios – a 'shock' outcome and 'severe shock' outcome.

The UK's GDP would be 6% lower and 800,000 UK jobs would be lost, in the second situation. In contrast, 500,000 UK jobs would be lost and the value of the pound would fall by around 12% in the first scenario, according to the Treasury.

Osborne was joined by David Cameron at the 23 May event, with exactly a month to go before the historic ballot. "I believe leaving the EU would put our security at huge risk. That it would be the wrong track for Britain," the prime minister declared.

"Why? Because as we know, and as even leave campaigners now freely admit, we would lose full access to the European single market. We would be abandoning the largest market place in the world, half a billion people."

The official Brexit campaign, Vote Leave, hit back by claiming the real risk to the UK would be to vote 'Remain' and pay the bill for the euro's failures.

"Instead of talking about forecasts and woolly predictions, we should instead talk about what is happening now. It is a fact that – every week – we send millions to Brussels. That is what is happening right now," a spokesperson for Vote Leave said. "The same old scare stories simply don't wash. The real risk to the economy is to stay tied to the failing single currency with an obligation to pay its bills. That's why the safer choice is to take back control of our economy by voting to leave the EU on 23 June."

George Osborne
Conservative Chancellor George Osborne Suzanne Plunkett/Reuters