LONDON (AP) — British Prime Minister David Cameron has warned that Britain would be plunged into a "do-it-yourself" recession if it votes to leave the European Union in the June 23 referendum.

He said Monday that choosing to leave the 28-nation bloc would be a "self-destruct option" for Britain.

The referendum is one month away and both sides have ramped up campaigning in recent days.

Cameron spoke after Britain's Treasury published an analysis warning of a lengthy recession and the loss of up to 820,000 jobs if the country votes to leave.

The analysis said leaving the EU would also cut house prices by between 10 percent and 18 percent and lead to more public borrowing.

Iain Duncan Smith, a leader of the "Leave" campaign, said the analysis was "deeply biased."