In a letter sent on Wednesday to the Ministry of Finance, which has made it public, the European commissioners for economic and financial affairs and for the eur,o Pierre Moscovici and Valdis Dombrovskis, state that they want to know "why Portugal is planning a reduction in the structural deficit in 2016 well below that recommended by the European Council in July."

In the document which is addressed to the minister of finance, Mário Centeno, the commissioners recall that on 14 July the European Council recommended a reduction of 0.6 of a point in the structural deficit, which strips out the effects of the economic cycle.

The draft 2016 state budget sent to Brussels on Friday foresees a reduction in the structural deficit to 1.1% of GDP, from 1.3% last year.

"In our preliminary analysis the reduction foreseen in the structural deficit is well below the 0.6 recommended," the letter states, adding that under a 2013 regulation if the commission finds “a serious disregard” for budget obligations foreseen in the Stability and Growth Pact it must "recommend" that the government in question send a revision of the draft as soon as possible. Before that, it notes, a request is made for clarification - which in this case should be sent by Friday.

"The European Commission wants to continue a constructive dialogue with Portugal with the objective of a joint understanding," the commissioners write.

They also note that Portugal's excessive deficit was not corrected by the 2015 deadline set for the previous right-of-centre government, prompting the commission to recommend extra measures in the 2016 budget, in line with euro-zone rules.

The Ministry of Finance has told Lusa that it will respond to the questions put by the commission.