A group of partners at Dundas & Wilson are leaving the firm ahead of its merger with CMS Cameron McKenna, which goes live next year.

It is understood that a group of senior partners, including former chairman David Hardie, will not be joining the new firm. Meanwhile, another group of partners have not received offers to move across once the merger goes live.

Hardie declined to comment when contacted by Legal Week.

The Scottish firm will combine with CMS in May, creating a firm with turnover of around £270m.

CMS is also understood to have agreed a lock-in with Dundas partners where they will be contractually held in the firm for a period of time on a particular level of pay, according to sources familiar with the deal.

It is thought the arrangement will be similar to that put in place by Pinsent Masons and McGrigors when the two firms merged last year.

Dundas & Wilson refused to comment.

From the go-live date on 1 May, Dundas' Edinburgh and Glasgow offices will take on the CMS banner but will retain the Dundas name for a transitional period of six to 12 months, while the Aberdeen and London offices will become CMS.

The firms said that no decision had yet been taken on any potential redundancies. Speaking at the time of the merger announcement, Dundas chairman Laurence Ward said: "There are still many fine details to be worked out."

Partners at both firms voted on the tie-up this month. Eighty percent of the CMS UK partnership were required to vote in favour of the deal for it to go through, while at Dundas the threshold was 75%.

In a statement, CMS said the deal would take partner count across the network to 830, with a total of 5,600 employees across 57 offices.