With both sides continuing to trade blows over the merits of their arguments, the UK parliamentarian said, "The great Euro campaign has reached a new low, no idealism from either side, only low-grade statistics and even lower grade politics."
Salmond added, "Neither campaign has inspired enthusiasm. They both trade in fear. Indeed, it is almost as if 'Project Fear' from the Scottish referendum had been split in two to make up both sides of the Euro poll."
In a newspaper article, he writes, "The Remain campaign is increasingly confident and very pleased with itself. It should not be. The pro-Europeans should be a mile ahead. The Out campaign has totally failed to offer any coherent vision of what life would be like outside the European structure."
Salmond, who served as Scotland's First Minister from 2007 to 2014, says, "Thankfully, the EU debate in Scotland has been largely free of the overblown rhetoric emanating from the south."
Speaking in Brussels earlier this month, Salmond warned that a Brexit would lead to the "lunatics running the asylum", but criticised the Remain campaign run by the Conservatives for "outlandish scaremongering."
Meanwhile, in a new report released on Monday, the UK Treasury warns that UK economic growth could be between 3.6 and six per cent lower after two years if the UK votes to leave the EU.
It also warns that the value of the pound could fall by 12 per cent and that house prices could fall by between 10 per cent and 18 per cent. These effects would also see unemployment rise and wages fall.
The report and its assessment techniques were authored by Charlie Bean, former Bank of England Deputy Governor.
Reacting to its conclusion, former UK work and pensions secretary Iain Duncan Smith said, "This Treasury document is not an honest assessment but a deeply biased view of the future and it should not be believed by anyone."
Further reaction came from Raoul Ruparel, of the UK-based think tank Open Europe, which campaigns for reform of the EU.
He said, "It's incredibly hard to predict the short-term impact of Brexit on prices given that this is an unprecedented event. It seems likely that there will be some devaluation, however, it's hard to say how large this [might be, and] we don't know whether this will be temporary and whether or how it will pass through to prices.
"Analysis suggests the pass through is far from perfect and can take years at times, by which point many other factors come into play."
It also emerged on Monday that the number of FTSE 350 company boards that believe EU membership is good for their business has dropped significantly over the past six months.
The biannual FT-ICSA boardroom bellwether survey, which surveys the FTSE 350, reported a substantial fall in the number who believe their company benefits from EU membership, to 37 per cent down from 61 per cent in December 2015.
Approximately 43 per cent said they believe a UK exit would be potentially damaging, with more than twice as many (55 per cent) of FTSE 100 companies believing that EU membership has a positive impact compared with 24 per cent of the FTSE 250.
Elsewhere, in a TV appearance on Sunday, UK Prime Minister David Cameron said that the upcoming EU referendum was more important than a general election, adding that "if you don't like the government, you can always get rid of them in five years' time.
"Whereas if we make this decision to leave the EU and get out of the single market and hit our economy and hit jobs, it would be very, very difficult if not impossible to reverse that decision."