Power brokers in the corridors of Brussels are sharpening their weapons as the fight for control of the $90 trillion euro-denominated swaps clearing business intensifies. Officials in the European Union, long irked that most euro swaps are cleared at London’s LCH, are pressuring banks and buy-side firms to shift contracts to Frankfurt’s Eurex.

Their persuasion tactics range from constructive engagement to veiled threats. In response, banks are warning law-makers that a forced migration of swaps