"From Europe we have the umpteenth unacceptable interference by unelected officials", Salvini said.
5-Star's parliamentary party leader Danilo Toninelli told state television Rai: "The only way to get a serious government is to return to the polls".
The League and Five-Star have held six days of talks aimed at putting together a coalition government to end 10 weeks of political stalemate following an inconclusive election on March 4.
There was still no word on the thorny issue of who would be premier - a job that Di Maio and Salvini both covet.
The document also contained a plan to ask the European Central Bank to cancel Italian government bonds worth €250 billion it bought under the quantitative easing programme.
The ideas in the draft program underscore the great difficulties in finding the resources needed to pay for promises the two rival parties made to their voters during the campaign.
The parties are still trying to find the right balance between their two policy platforms, Salvini added.
According to Italian media reports, their nominee for Prime Minister is likely be from a "third party" and will have to be able to make the eurosceptic nature of the new government workable with Brussels. Italy's debt mountain totals more than 130 percent of national output is the highest in the Eurozone after Greece's. "The European Union would not be complete without the Italian nation", Juncker said.
Both M5S and League have a deep history of Euroscepticism and while 5-Star has moderated its position considerably in the past year, rowing back on a previous plan to hold a referendum on Italy's membership of the currency bloc, the League still wants to leave the Eurozone as soon as is politically feasible. The policy program will probably be published Thursday, 5-Star said.