Freeholders changing lease terms

[Suetheramble]

I live in a block of flats and the freehold has recently changed hands. The new owners are planning to change several terms in the lease ie the maintenance to be paid monthly instead of every 6 months.
I informed them I happy paying every 6 months as per the lease they have advised me that it will be voted on at the AGM meeting but as only 15% of shareholders bother/able to attend the AGM it will be a vote of a few people.
I was of the understanding that to change the terms of a lease there had to be 100% backing of all shareholders.
Does anyone know what is the correct procedure to change the terms of the lease?

[themas]

Ring these people up for advice:

http://www.lease-advice.org.uk/

or else contact a solicitor.

[Suetheramble]

Thank you - a most helpful site