The group, which is looking for a new public affairs agency, is a coalition of patient organisations, research charities and medical device manufacturers working for greater availability of medical technologies.
It has invited a closed list of seven agencies to pitch for its account, with a view to making an appointment in May.
An MTG spokesman said: ‘We’ve had five good years with Weber Shandwick. It has helped professionalise and improve the work of the MTG, but we thought it would be good to get some fresh ideas.’
The group’s key requirement is for lobbying support, with a smaller element of media relations.
The search for an agency comes ahead of changes to the way the NHS commissions services.
Strategic health authorities and primary care trusts are set to be abolished by next month. Services will instead by commissioned by more than 200 local clinical commissioning groups made up of GPs, hospital doctors and nurses, and other specialists.
Nationally, the new NHS Commissioning Board will commission specialised services.
The MTG spokesman said: ‘Traditionally, we have spent a lot of time lobbying central government. Now we’re going to have to take a step back from that and start lobbying direct to the NHS a lot more.’
The winning agency will report to the management committee of the MTG, which is chaired by Heart Research UK’s Barbara Harpham.
John McLeod, chairman of Weber Shandwick's public affairs division, said: 'Weber Shandwick has helped professionalise and grow the MTG and bring a real purpose to the group. However, within the resources available, WS has agreed with the Group that it will not be possible to take it any further. WS leaves the Group in good shape and has wished it well for the future.'