Pearse Doherty has written to the Finance Minister calling for the government to add further supports to those who have lost jobs and businesses during the Covid-19 pandemic.
The Sinn Féin finance spokesman's seven page letter to Paschal Donohoe, urges the minister to take a tougher stance with Irish banks, which he says have "failed to keep promises that they would offer mortgage-payment breaks to affected customers, despite statements to the contrary from Government".
Adding that other lenders, companies and landlords have been asked to show understanding to citizens who have lost jobs with little guidance on how this should be done.
Mr Doherty writes that the response of Government, a new payment of 203 euro per week for those temporarily laid off, is "totally inadequate".
Sinn Féin proposes an alternative Income Support Scheme for 20 weeks, with the ability to extend, that would guarantee 100 percent of earnings for workers with annual earnings of up to €32,500, which equates to up to a maximum of €525 per week.
This payment would also be open to those in the gig economy and the self employed.
For businesses and firms, Sinn Féin say supports should be based on certain priorities, as it "is imperative that such supports do not simply amount to a corporate bailout for the banks, big business and their shareholders".
They suggest that any financial assistance provided to businesses should be conditional on their agreement to participate in the Income Support Scheme, with workers kept on employers’ payroll with no lay-offs during or after the emergency, and where businesses deliver public goods, such as housing or utilities, on the basis of cash for equity, the State could acquire stakes in these firms.
The letter also notes that COVID19 and the aftermath will be a Europe-wide problem and the finance packages needed to deal with the crisis will need to be dealt with at a European level.
With regards to borrowing, Sinn Féin say that as Ireland's spending powers are constrained by the EU, an EU level response is required.
Mr Doherty suggests the way to avoid a repeat of the 2011 financial crisis, is through the joint issuance of bonds at a European level, which would not have the "unacceptable conditions including austerity and stigma" attached.
Meaning the European states would borrow together, with repayments due only when Member States have recovered.
Such a financial arrangement, already being suggested by Italian Prime Minister Giuseppe Conte, would be hard to coordinate, due to Germany's opposition to the idea, however some reports already suggest Chancellor Angela Merkel may soften on the stance as the pandemic worsens.
"It is essential that Government delivers a financial package that equates to the scale of economic damage," Mr Doherty writes.
"This will require a multi- billion-euro emergency package to support our health service, offset loss to household incomes, provide liquidity to businesses, support our health service and sustain jobs during the recovery once this emergency ends."
Any financial package with the ability to deliver on these kind of priorities will require Dáil review, through either emergency legislation or a much speculated on March Budget.
Sinn Féin are calling on the government to prepare such legislation in the coming days so it can be scrutinised by the Dáil before the end of this week.