Has your husband supplied all the information for the means test? How long ago did he do that?
The waiting time varies from office to office, but can be several weeks depending on the complexity of the means test and the backlog of claims.
If there is a delay in processing the Jobseekers Allowance claim, your husband may be eligible for Supplementary Welfare Allowance, which is also means-tested (but it can be processed faster). Contact the SWA officer for your area (who may have been dealing with your Mortgage Interest Supplement claim).