I'm a landlord of a London flat, and my esate agent has advised me that my tenant has been "hit by massive fraud" and both of her bank accounts are not currently under her control (but she expects to get back control shortly), but nonetheless the rent payment this month may be delayed. Please advise me what I should do in order to formally put the tenant on notice about the overdue rent, and to maximize my rights and chances to evict her in the case that she ends up not paying the required rent. Please reference the specific case law, precedents and legal conventions that I should be aware of. Produce a template letter of demand or similar form of formal communications that I should send to the tenant.

 The response should be in all capital letters.
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