Ask an Property Solicitor. Get an Answer ASAP.
Has the landlord offered you the option to purchase the freehold?
Has this been discussed with the other leaseholder?
No the landlord has offered me a deed of variation in relation to the ground rent. I have not discussed the option to buy the leaseholders. I own 4 out of 8 flats in the block. Do all leaseholders have to buy the freehold or can I just purchase my flats.
You will need to speak with the Landlord to see if he is willing to sell the freehold, and if so at what cost. You will then need to discuss with the rest of the leaseholders if anyone else is interested in purchasing with you. The option needs to be provided to all leaseholders. If they refuse then you can buy on your own, but you will have to buy the whole building, not just your flats.
Otherwise it may be easier to just proceed with the deed of variation - you will want this for all 4 of your flats separately.