Rent arrears

Rent Arrears

My tenants are in arrears of 6 weeks rent (rental is 1,500 pcm) - none paid 1st April and May when due. I am selling the property to a developer who is going to demolish the block - completion date is 28 June 2013 which the tenants have been aware of for over a year. I have given them 2 months notice in writing on 23 4 13 as per Tenancy agreement. The Deposit held is £2,147 (DPS)
The lead tenant says they cant afford to pay the rent as they need to save for the deposit and initial rent to move out on 23 June 2013 as requested. Clearly it is a blackmail situation as they know I want vacant possession by end of June . He suggested I keep his deposit of £2,147 instead of the rent due - there will be about £4,100 rent due by the end of June.

The tenancy has run from 1 Nov 2010 and renewed annually . Rent was paid on time until the beginning of this year when it has usually been a month late and paid in instalments.

I am obviously keen to get vacant possession by 28 June 2013 - bit nervous re leaving the deposit as part payment of rent.

How best to proceed ?

CK