I would talk to your Landlandy and tell her that as the house is up for sale and you have the opportunity to go elsewhere you will be moving out.I would likely suspect you would have to give 4 weeks notice but you could probably dispute this as she put the house up for sale without notifying you.Then move out and she will be an extra 490quid out of pocket per month until the house is sold
Sorry had the same situation here and the new owner wanted to increase the rent instantly
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