Apple’s lawyers are having a busy month. Hot on the heels of the US Senate hearings into alleged tax-avoidance, the Financial Times reports that a preliminary  enquiry into whether Apple has been guilty of anti-competitive practices in Europe has moved to the next stage.

We reported back in March that the European Union was considering whether Apple’s contracts with European phone carriers may contravene anti-trust regulations after informal complaints were received from several French carriers. The complaints alleged that Apple took advantage of demand for the iPhone to impose conditions on carriers that put competitor manufacturers are a disadvantage.

The EU has now asked carriers across Europe to answer a series of questions about the alleged practices in order to decide whether or not to open a formal anti-trust enquiry …

Essentially, the allegation is that Apple said to carriers, if you want to offer the iPhone at all, you have to buy lots of them, and you have to promote them heavily. The suggestion was that carriers were effectively forced to push iPhones over competitor handsets in order to recoup their investment.

Carriers have until June 17 to return the questionnaire.

Anti-trust authorities in Italy last year fined Apple a total of $1.5m after finding the company guilty of pushing AppleCare warranties without informing customers that EU law already provided for two-year warranties as standard.