ALEX Salmond has launched a withering personal attack on David Cameron, branding him a "fearmonger" who personifies everything that is wrong in British politics today.

Ahead of the Prime Minister's impending visit to Scotland, the First Minister branded Mr Cameron a "substantial liability" to the No campaign.

And he predicted Mr Cameron's trip north of the Border would be counter-productive as it would continue the "same rut of negativity".

"Scotland has moved beyond the fearmongering of David Cameron," he declared.

"He personifies everything that's wrong with the politics in this country at the present moment, where a Tory prime minister with minimal, negligible support in Scotland can command political authority over our country, a country which has never and will never elect people like him to govern us.

"That is the democratic deficit, which is one of the key arguments which is propelling the Yes campaign forward."

The Coalition hit back, with a senior Whitehall source decrying the SNP leader's negativity.

He said: "More people in Scotland voted for the parties of the UK Government in the General Election than voted Alex Salmond for FM a year later.

"It is up to him if he wants to play the man but we will continue to play the ball and set out the positive case for Scotland."

In his wide-ranging broadside against the Prime Minister, Mr Salmond also said:

l The PM had not got the "guts nor the gumption" to accept his challenge to a head-to-head TV debate;

l The Tory leader would come to Scotland to argue it either did not pay its way or could not stand on its own two feet, and said his visit would be "seen as ridiculous by the population at large";

l That the No camp was ­delivering the "same old negative whining and running down of Scotland";

l His Team Scotland would engage constructively in post-Yes vote talks but that "Trident is non-negotiable outwith the terms of the first term of the Scottish Parliament", when it will be removed;

l Insisted on the currency union, saying that on the day after the referendum vote Coalition ministers would be "singing an entirely different song in the face of a Yes vote";

l Insisted, ahead of an appearance today by Chancellor George Osborne and Treasury Permanent ­Secretary Sir Nicholas Macpherson before the Commons Scottish Affairs Committee, that Sir Nicholas's published memo ruling out a currency union was a "campaigning tactic instructed by the No campaign".

The First Minister added: "Westminster politicians should learn and understand the ability of bogeymen to scare the Scots … these days are over."

Earlier, Alistair Carmichael, the Scottish Secretary, updated his Cabinet colleagues on the UK Government's efforts to keep Scotland within the UK.

According to Mr Cameron's spokesman he spoke about the forthcoming publication of analysis papers and the "importance of keeping on making the arguments in favour of retaining the United Kingdom".

One key analysis paper is due for publication after the May 22 European parliamentary elections but before the end of this month.

It is the result of intensive number-crunching of the Scottish Government's White Paper by the Treasury's top economists.

In the past the department's experts have come up with figures showing what the cost to Scots would be of independence,

It is suggested that this time round they will produce a number, showing how much people in Scotland benefit per capita from being part of the United Kingdom.

It is thought the figure will run into thousands of pounds.