Stock exchanges and asset managers have clashed ahead of European Union talks this week over how much information should be made available to investors to find the best deals on Europe’s fragmented stock markets.

On Tuesday, the European Parliament and EU states begin talks to finalise a reform of the bloc’s securities rules, known as MiFID, aimed at improving the efficiency of the capital market, which will face competition from London after Brexit.

It includes mandatory contributions by trading platforms to the “aggregate tape” or stock price record, a long-standing feature of US markets. The proceeds of the tape would be shared among participants.

In initial positions, Parliament supported a tape providing real-time prices of completed stock trades – currently many investors receive only pending prices – and an in-depth view of pre-trade prices.

EU countries have also supported a tape with real-time data on completed equity trades, but with less comprehensive pre-trade data.

Exchanges that capitalise on market data say parliament goes further than transparency by providing investors with a trading tool.

But the Association for Financial Markets in Europe (AFME), whose members include global banks and asset managers, said on Monday that an “ambitious real-time pre-trade data feed” would help reverse a worrying trend where European stock markets are “noticeably less dynamic” than their US counterparts.

The European Fund and Asset Management Association (EFAMA) also supports Parliament’s position, stating that liquidity in European stock markets has declined by 25% since 2013, compared to a 23% increase in US markets, and a number of factors are contributing to this.

Negotiations will also seek to iron out differences over whether brokers should be banned from receiving commissions for sending stock exchange orders to a particular platform.