Despite already employing dozens of in-house spin doctors, the government wants to spend around £1m a year for the next four years on outside “media services”.
The work will involve issuing press releases on behalf of 250 public bodies as well as monitoring coverage in newspapers and online.
Opposition parties united to condemn the spending, with the Scottish Conservatives describing it as “patently absurd.”
Scottish Labour said the decision to find another £4 million for spin in the run up to the independence referendum campaign would “raise eyebrows.”
The government, which has put the work out to tender, confirmed: “We anticipate that the potential annual spend across around 250 public bodies may be up to £1,000,000.”
They added that the media services would include news release distribution, press cuttings, broadcasting and online news monitoring and social media monitoring.
In 2010, the Scottish Government admitted it employed 46 communications officers at a cost to taxpayers of £2.4m annually.
A further £822,000 was spent on special advisers for ministers.
Other public bodies in Scotland employ hundreds more spin doctors, including NHS boards which spend £2.6m a year on media staff.
Scottish Conservative finance spokesman Gavin Brown said: “At a time when public services are being squeezed and families across Scotland are having to tighten their belts, I think there will be astonishment that the Scottish Government has a spare £4 million to spend on this.
“The Scottish Government already spends a substantial amount of taxpayers’ money on media services and their press team.
“To spend an extra £4 million is patently absurd.”
Ken Macintosh, Scottish Labour’s shadow cabinet secretary for finance, said: “Given the difficult decisions faced by hard-pressed families in Scotland, it is worrying that the SNP government seems more concerned with its image than the actual work it should be doing to help people through these tough economic times.
“Many people already believe the SNP spend far too much taxpayer’s money on spin doctors and that is before throwing millions more at their attempts to make their bad decisions look good.”
Mr Macintosh added: “This multi-million pound expenditure by the SNP in the run up the referendum campaign will certainly raise eyebrows.”
Leader of the Scottish Liberal Democrats Willie Rennie MSP said: “This seems excessive.
“At a time of great financial challenge, it will be difficult for anyone struggling to make ends meet to understand why the Scottish government is spending £4 million on items including monitoring their Facebook page.”
One public relations insider, who asked not to be named, said the contract was “very surprising”.
“They want media monitoring for agencies as diverse as Forestry Commission, Cycling Scotland and Northern Lighthouse Board. They want agencies to help in distributing Scottish Government media releases.
“To my knowledge there is no one agency in Scotland that can provide all these services under one roof.”
A Scottish Government spokesman said: “Any suggestion that this contract is about hiring additional staff to carry out press office functions is completely inaccurate.
“The contract covers auxiliary services already provided by outside contractors.
“This contract renewal will enable up to 250 public sector organisations to collaboratively purchase a range of integrated services which would otherwise have to be negotiated and purchased individually.
“This delivers major savings to the public purse and is part of our commitment to opening up public sector contracts to businesses of all sizes.”
The Scottish Government said “news distribution” would be among the services available through the contract though said this would not involve the hiring of press officers or PR staff.