work permit and FLR/Entry clearance

[workpermitinquiry]

Hi,
I am a PhD Student (on Further Leave to Remain visa) waiting for my viva (which is going to happen in 3 weeks time). I have been offered a job and my Employer had applied for a work permit and it has been granted now. The work permit document outlines the requirement for me to get a Further Leave to Remail(FLR) on the work permit.

However, I would like to know If I can get a Work permit based FLR (hence switch from student FLR to Workpermit FLR) before I finish my Viva? As waiting for Viva (and doing afterwards corrections) will involve another 4-6 weeks.

It is very important decision for me to make at this time and juncture and I will appreciate any bit of advice I can get it from you.

Thanks

DT