The leader of Germany’s Social Democrats (SPD) took aim at U.S. technology firms Apple, Facebook and Google on Thursday, saying a strong Europe was needed to make sure they stick to the rules.

Axar.az reports citing Reuters that, Martin Schulz, who hopes to persuade his party to approve talks with Chancellor Angela Merkel on forming a new coalition, told a congress of his SPD party that Ireland was complicit in allowing companies like Apple to avoid billions of euros in tax.

He also called for the creation of a European finance minister, who should fight tax evasion by reining in the race to the bottom in tax policy among member states.

“Only a strong Europe can force platform giants like Facebook and Google to respect our rules and basic rights,” he said.