In a double blow for Birmingham firm Edge & Ellison, five of its key Birmingham corporate lawyers, including high-flying Midlands partner Chris Rawstron, the head of its Birmingham corporate department, and partner Russell Orme, are defecting to Dibb Lupton Alsop while London corporate finance partner David Mandell has moved to SJ Berwin.

Dibb Lupton Alsop's poaching coup marks the first real step in its attempt to lead the pack in Birmingham since it opened there three years ago with the takeover of Needham & James.

Nick Seddon, Dibbs' Birmingham managing partner, said there were further appointments in the pipeline as the firm aimed to be first or second in every area in which it operates, including the Midlands.

“I hope that this latest move indicates the seriousness of our intention,” said Seddon.

Observers believe Rawstron could form the nucleus around which Dibbs could eventually build a strong corporate practice in Birmingham.

But Wragge & Co managing partner Quentin Poole poured cold water on the firm's ambitions in the area. He said: “There is a 'big four' [Wragges, Pinsent Curtis, Eversheds and Edge & Ellison] in Birmingham and the other firms are a long way behind.”

Poole pointed out that while the top four all have well over 300 staff, Dibbs had only around 120. He said: “We have recruited over 50 lawyers in the last 12 months. Chris Rawstron is an important signing, but just recruiting the odd partner here and there is not going to make the difference. The big four are accelerating away from them. Dibbs needs to do something big to have any effect.”

Edge & Ellison is bound to be hurt by the moves from Birmingham, particularly that of Rawstron, who, it is understood, tendered his resignation when his friend and colleague Russell Orme departed.

Edge & Ellison management board wants to concentrate on public company clients and claimed that it told partner Russell Orme and David Mandell in London that their type of work on small buyouts and owner-managed companies no longer formed part of the firm's strategy.

Rawstron is being held to his 12-month contractual notice, so will not be able to join Dibbs until the end of this year. Three assistants who worked with Orme and Rawstron – Charles Cook, Mark Beardmore and Ray Wearmouth – will be joining Dibbs in March.

Edge & Ellison senior partner Digby Jones said: “We are committed to a strategy decision of acting for public companies and institutions.” He added that the direction in which both Mandell and Orme wanted to go was not consistent with that strategy.