The Financial Services Authority (FSA) has provoked a storm of protest from City law firms with its new rules on short-selling.
Since making the shock announcement last week, the regulator has been inundated with questions and yesterday was forced to release a second statement to clarify its position.
The new regime, which comes into force on Friday (20 June), will require investors to disclose significant short positions in companies undertaking rights issues.
But lawyers have criticized the rules for being unclear and for being rushed out without consultation. Several firms including Herbert Smith, Linklaters, Slaughter and May and Travers Smith contacted the FSA this week to demand an explanation.
Herbert Smith financial services and regulatory partner Patrick Buckingham said: "It is unprecedented for the FSA to come out with a new rule without there being any consultation process beforehand."
The announcement comes after rights issues by HBOS and Bradford & Bingley were threatened by plunging share prices thought to have been caused by hedge funds short-selling their stock.
Travers Smith corporate partner Richard Spedding said: "We were straight on the phone to the FSA as soon as we heard about it and our hedge fund clients were straight on the phone to us.
"It has been a fairly quick fix measure that has asked more questions than it has answered."
The FSA's second release was in the form of a three-page question and answer document which admitted: "We have received several queries relating to how the disclosure regime will operate in practice."
Short selling is an established market practice which sees traders borrow shares from long-term investors to sell and then buy back more cheaply when the price falls.