Is it normal, what should be my answer to this question?
You may want to read this article http://www.contractoruk.com/agencies/recruitment_agency_tric...
You may always try to dodge the question by providing the rate you want/expect.
Note that the law may limit what recruiters are allowed to ask in recruitment process. You need to check regulations in UK.
You may want to read this article http://www.contractoruk.com/agencies/recruitment_agency_tric...