We can't seem to find the original contract, we just have the memorandum, however I am pretty sure it is a fixed-term Assured Shorthold Tenancy Agreement.
I've attached the memorandum of renewal that we signed, the only break clause is the one stipulated about a house purchase.
I just realised that the landlord didn't technically agree, he sent the following:
"Dear XXXX & XXXX
Many thanks for advising that you wish to terminate the tenancy agreement by providing two months notice.
Please let me have a date when you wish to vacate in order that Hamptons are able to arrange to market the flat and arrange viewings.
We wish to wish you both all the very best for the future.
I have found the original contract now, it is definitely an Assured Shorthold Tenancy Agreement. I would be interested in knowing if there is any way we can break it early still. I can send you the contract and memorandum via E-Mail if that is easier?