Not sure if this is O.T :- Rent review for shop premises in City Center.

That sounds a fair approach. I would tell the landlord of your plans to go to the board if agreement cannot be reached.

In article , Justwondering writes

Rents are normally reviewed up to the level of the most recent comparable local property. Some landlords will then add a bit more.

It is difficult to get hold of evidence because reviews are not publicised. If you are sure you are being asked too much, it may be worth paying a valuer to negotiate and possibly prepare a case for arbitration.

In article , news writes

The lease should include a provision that solves the problem. e.g. for each party to appoint a valuer to argue their case. In reality, I would expect each valuer to reach a conclusion based on the evidence they can find and then have a quick chat with each other to compare notes, possibly splitting the difference if any. Valuers will make some calls to other valuers, or letting agents, to get the evidence - something which is not easy for the individuals to do successfully.

After this, if agreement cannot be reached, the whole thing may go to a pre-defined arbitrator, whose decision would be final.