Europe’s top markets regulator has said that it will start work immediately on amending key Mifid II rules that were sent back to it for revision earlier in March, but warned that proper procedure is not being followed.

The European Commission sent three regulatory technical standards from the review of the Markets in Financial Instruments Directive back to the European Securities and Markets Authority on March 14. The standards as written, the EC said, did not adequately reflect concerns from the European Parliament and Council, and it urged a more cautious approach in order to avoid damaging liquidity.