Financial talk

I have given my boss a month notice after consulting the financial director for advise, so that the company has enough time to find someone to replace me. 3 days later I received a letter from my boss informing me that the company does not need me anymore due to the lack of workload and that they only need a week notice. Can someone advise me of my rights, either his action is legal especially after I have handed my notice before he dismisses me. I have worked for the company for 10 months and my contract does not specifies the notice period so I believe I cannot call this unfair dismissal. Please help!