Mr Salvini criticised the Brussels bloc for its lack of support over the latest migrant rescue boat docking in the Sicilian port of Catania last week.
The Italian Interior Minister refused to give an authorisation for most of the migrants to disembark the boat until Italy received guarantees from other EU countries they would share the burden of asylum seekers.
He told supporters in Pinzolo: “Europe has demonstrated once again to be unprecedented filth that doesn’t deserve our money.
“From the first to the last one of them, no one cared.
“And I ask for your mandate to re-discuss the billions Italy sends to Brussels every year.
“I think the time has come to make some cuts to funds given to a useless institution that turns its back when we most need it.”
Repeated protests tried to pressure the authorities into letting the migrants ashore.
Only some children and others with health problems were allowed to disembark the rescue ship.
Eventually, all migrants were allowed to disembark on Saturday night a five-day dispute between the EU and Mr Salvini.
On Thursday, with no solution in sight, Italy’s Deputy Prime Minister Luigi Di Maio said the coalition government, formed of the Five Star Movement (MS5) and La Lega, would vote to suspend funding to the EU next year.
They said they would do so if partners do not agree to take in migrants now being held on a coast guard ship in Sicily.
In a video posted on Facebook, Mr Di Maio said: “If tomorrow nothing comes out of a European Commission meeting on redistributing migrants from the Diciotti ship, the 5-Star and I will not be willing to give €20bn each year to the EU.”
Senior officials from 12 member states met on Friday in Brussels to try and thrash out a deal over the migrant boat Diciotti, which the Italian government refused to accept.
However, the emergency meeting in Brussels ended without any agreement, according to the European Commission (EC).
This has triggered an escalating spat, with one European Commission spokesman Alexander Winterstein claiming that “threats in Europe do not lead anywhere”.
Mr Winterstein said he did not “want to go into hypothetical scenarios” on what might happen if Italy doesn’t pay its £18bn contribution.