Members of the 'remain' EU campaign have used "spin, smears and threats" to try to cajole the British people according to the Work and Pensions Secretary Iain Duncan Smith.
Mr Duncan Smith warned that the 'acrimonious tactics' of the pro-EU camp, which he said are based on "desperate and unsubstantiated claims", risks damaging the Government beyond the June 23 referendum.
Writing in the Daily Mail, he also accused the Government and the 'remain' campaign of staging a "series of stunts" using big business, finance chiefs and European leaders to "bully" those considering a vote to leave, into fearing for their future prosperity and security.
Mr Duncan Smith said the debate ahead of the referendum should be conducted with respect and warned rivals not to "indulge in scaremongering".
He wrote: "The acrimonious manner in which all this has been conducted is troubling, and will I fear have consequences long beyond June 23.
"After all, such desperate and unsubstantiated claims are now being made that they begin to damage the very integrity of those who make them in the eyes of the public."