The Financial Conduct Authority unveiled plans to publish a daily summary of trading in UK shares starting Friday, releasing a year of backward-looking data to help investors gauge trading volumes. This interim step precedes a complete consolidated tape for equities, a single feed of trading data for stocks.

The regulator will also set out the scope of the feed, likely including both pre-trade and post-trade data. Whether pre-trade data should be included has sparked debate in the City of London, with broad agreement on post-trade transparency but disagreement on whether banks should disclose pricing data before trades.

London Stock Exchange Chief Executive Officer Julia Hoggett lobbied the FCA to proceed cautiously, setting four conditions including that all price-forming venues contribute, operational resilience, prevention of high-frequency traders front-running the tape, and revenue sharing to compensate venues. She threatened to seek government intervention if the FCA doesn't protect market integrity.

The plan aims to increase transparency in UK equity markets, stem the flow of companies leaving the exchange, and encourage more listings. Europe's consolidated tape is set to go live in September.