Minister for Finance Michael Noonan has said that voters should look to Portugal as an example of how "political instability leads to economic instability" as Fine Gael prepares to further amplify risks to the economy in the election debate.

Party sources say the coming week – the last full week of campaigning – will see attacks on opponents and warnings of international risks intensify.

Fianna Fáil, in particular, will be singled out for attack, which sources in Micheál Martin's party say they are expecting and are prepared for.

Fine Gael Ministers, TDs and senior party figures have also begun to raise fears of international risks, such as the slowdown in the Chinese economy, trouble in financial markets and a possible British exit from the European Union.

The threat of the latter will be unlined when the Taoiseach attends a meeting of the European Council late next week, at which British prime minister David Cameron's reform package will be discussed.

When asked if Fine Gael will deploy fear as the election enters its final stages, one party source said: “I wouldn’t describe it as fear. I would describe it as reality.”

Labour sources say Brendan Howlin will make similar arguments. The junior Coalition party is also expected to increase its attacks on Fianna Fáil, and in particular how Mr Martin proposes to form a stable government.

“Our version of ‘project fear’ is more likely to call out the choice he says he is offering and say that all it is a government involving the Shinners and the ragbag,” claimed one Labour source.

Mr Martin has consistently said he will not enter into Coalition with Sinn Féin.

Other Labour sources said the party will raise the possibility of no government being formed after polling day due to a hung Dáil.

In a statement, Mr Noonan said "voters should look to Portugal if they want to see how political instability leads to economic instability". He claimed the alternative on offer in Ireland is "Fianna Fail and an unknown combination who have no credibility and no plan for the economy".

Last October, Portugal was plunged into political crisis following an inconclusive election. A conservative government was eventually replaced by an administration made up of socialists, communists and the radical Leftist Bloc.

Earlier this month, the European Commission approved Portugal's 2016 draft budget after the new government promised to hike indirect taxes to meet EU budget rules while also easing austerity.