Applying for Minor British Citizenship with Expired Indian Passport

Dear Moderators,

My son is born(September 2011) in the UK and he had a valid UK visa all the time up to July 2020. I and my wife applied for ILR in June 2020 and received approval(& BRP) in February 2021. We have submitted an application(MN1) for 'Register as a British Citizen' for my son in March 2021 and his biometric appointment is due by 15th April 2021. My son's current Indian passport is due to expire on 1st June 2021.

Can I apply for my son's British Passport(once approval received as per process) with an expired Indian Passport? Would it be a problem to apply for British Passport without having a valid Indian passport(or an expired Indian passport)? Please advise.

Regards

Should be okay.

Thank you very much for a very prompt response.