I moved out mid way through a 12 month contract having agreed with the landlord that I would continue to pay the rent and re-letting fees whilst they searched for another tenant to take over the property. However after 6 weeks they have now decided to sell the house and are no longer looking to re-let. They are using me to carry the burden of the mortgage whilst they try and sell up. I am now going to be in a very tight financial position whilst they have changed the game. I'd like to know what are my options and what's the worst that could happen should I renege on the rent.

Where are you located? In most states the landlord is required to make a good faith effort to re-let the property when a tenant breaks a lease. However some states have no such requirement. So let us know where you are and then we can give you a better idea of your options.

I'm actually based in the UK.

In my contract it states that the landlord must give me 2 months notice if they wish to sell, which they didn't do. I only found out because I went on the letting agents website. The contract also says that they cannot unreasonably refuse my request to sub-let the property.

I am wondering now have they breached the contract by deciding to sell without informing me according to the terms of the contract and whether I can use this as a lever to get me out.

I'm not that familiar with the laws in the UK but it sounds like you have an advantage in this situation. If I were in your position I would speak to a solicitor about stopping the payments. Also I'm going to forward this to one of the members here who lives in the UK and may have more to offer.

Your landlord has clearly reascended the contract and as such you are no longer liable for any re-letting fees.
As for the outstanding rent, that's a different matter.

You need to read through your contract as I'm sure it covers what happens in cases like this.
Has the landlord given you notice of the sale ?

Get yourself some advice from your local CAB, they should have information of solicitors that can assist you with this if needed.

Thanks for your help. My landlord didn't give me any notice, I was still under the impression that they were looking for a new tenant. I only found out by fluke. I am not concerned about any re-letting fees since there will be no re-let, what I am worried about is how previously it was very likely that someone would take the property as it was a new build in a good, popular area. Whereas now I am footing the bill whilst they try and sell which could take months. My current thoughts are to try and get out based on the fact that by not telling me they have breached the contract. If that fails then I'd like to sub-let until the end of my contract in August. The contract specifies that they can't refuse a reasonable request to do so.