Thanks for your reply.
As the fixed term has expired, your Tenancy continues upon the same terms and the same rent, until either party serves Notice.
In these circumstances, even if the Tenancy agreement says otherwise, a Landlord has to give the Tenant 2 months Notice, such notice to expire on the day before the rent is payable.
Therefore, your Landlord has given you an invalid Notice in that it was only 1 month's Notice AND it should have expired on 31st July.
He is therefore under a duty to serve a further correct Notice on you, before you are legally obliged the property. Until this correct Notice expires, you are entitled to remain in the property and he can NOT increase the rent.
To comply with the law, your Landlord therefore has to give you Notice anytime before 31st July, giving you Notice to leave on 31st September.
If you yourself wished to end the Tenancy before this date, you could serve Notice yourself on the Landlord, at any time before 31st July, to leave on 31st August (a Tenant need give only 1 month's Notice to their Landlord after the fixed period has expired.
I hope this sets out the law and answers your question. If so, I would be grateful if you could leave positive feedback.