Hi Peanut,
I would send him written notice that if he fails to back pay all due and owing rent by [x date] and continue paying on time, his belongings will be sold. Just make sure you provide ample notice i.e. at least 3 weeks, and ensure that he receives the written notice before you sell or destroy.
Three weeks isn't long enough and you are not entitled to destroy his possessions. Have a look at the abandoned goods legislation but also if the gear is abandoned when you go, the agent must remove and store and can charge costs. 3 months is considered a reasonable time by agents, before selling the goods or disposing of them. Whatever the dispute, do all the right things even when taking risks such as might be seen in my suggestions. Who paid the bond by the way?
As 'co-lessees' you are jointly and severally required to meet the lease. I'd see whether the tenancy tribunal will hear the matter and to whom the bond will be returned if it is. I would ask the tribunal to make an order that he brings arrears to date and pays his share....It may not of course. That he is no longer living there does not stop his obligations under the agreement but enforcing it even as a small claim may be too costly. The tribunal was set up to help resolve the problems experienced in leasing, bad tenants and bad agents as well as things beyond one's control. Be clear in what you want in going to the tribunal and say so clearly in the documentation.
Another option perhaps too common in tenancy is to move out towards the end of the lease(in your case I'd be leaving the place in very good, photographed condition inside and out on the day you leave and preferably photographed also by another party and your acts observed and witnesses. ) but fore-saking the bond for the month's rent, leaving his gear there but safely outside the house, say in the back yard under plastic.. Tell him so.
Do it the day before you abandon it so he can't come in and damage the place.. Advise the agent you have gone. Another is to ask the agent to find other tenants and enable you to break the lease and tell you partner that this will be your last communication it's up to him to salvage his gear. It may be that the agent and he bump into each other if the agent is advised and some dealings go on there.
