Sinn Féin’s plan to spend an additional €22bn by 2025 have been branded as “dangerous and highly irresponsible” by leading economists and political opponents.

The party’s spending plans for the next five years are more than double the €11bn that the Department of Finance believes will be there to spend.

Sinn Féin proposes that, if elected, it will give away €2.4bn in tax reductions every year, and raise €3.8bn in tax increases every year.

The party also says that it would run a surplus every year, reaching €3.4bn by 2025. It insists that the costs of its proposed measures have been approved by the Department of Finance.

However, the department clarified that it did not cost the totality of the Sinn Féin package but rather it costed individual items and there was stinging criticism of the party’s spending plans.

Economist Jim Power said any party proposing additional spending within the €11bn ceiling is prudent but moving beyond that is highly risky.

“Any party going beyond that ceiling are dangerous and fiscally irresponsible,” Mr Power said.

He said many of Sinn Féin’s planned tax increases on financial institutions and wealthy individuals “fly in the face” of a growing economy.

He also questioned the legality of the party’s intention to end the tax break being used by the bailed-out banks to avoid paying corporation taxes due to losses accumulated during the crash a decade ago.

Leading UCD economist Colm McCarthy said “Assumptions that there is a big, jewel-crested chest in the Department of Finance containing the €11bn are misguided.

It is merely a projection of what budgets will look like. There is no guarantee the money will be there.

“If tax revenues hold up and there is control of spending, then the €11bn could be there. But there has not been control on spending.”

There has also been sharp criticism from Fianna Fáil’s finance spokesman Michael McGrath, who said Sinn Fein’s manifesto is “the stuff of Santa Claus”.

He said the big lie of the manifesto is that the party is seeking to introduce €4bn in additional taxes and saying it will not hurt anyone.

“Where is the money coming from? This manifesto is dangerous and highly irresponsible and it narrows the tax base which is the very thing we should not be doing,” he said.

Launching the manifesto in Temple Bar in Dublin, party leader Mary Lou McDonald said Sinn Féin would “give workers and families a break, put money back into people’s pockets and fix the housing crisis”.

The manifesto also including plans to abolish the USC for incomes under €30,000 and also abolish the local property tax.