Porting landline number to third party when switching FTTP service from Sky to Plusnet

[#1]

I’m currently with Sky FTTP with Sky Talk (VoIP)  for my landline number. My contract is up at the end of February and I’m looking at alternative providers. Although I don’t use my landline that often I would like to retain the number and possibly port it to a third party VOIP provider such as Sipgate to handle incoming calls. 

My question is, if I decide to switch my fibre broadband service to Plusnet, how would I arrange to port my landline number to Sipgate without screwing up the switching of my FTTP service?

Can anyone help please?

[#2]

In theory, you request Plusnet to transfer your FTTP service. As part of that they will cease your phone service. You then have 30 days under the OFCOM 'right to port'; regs to port your number to another supplier. However Sipgate don't seem good at porting non-active numbers, A & A seem better. 

[#3]

@cookp 

Suggest you talk to Sky to confirm the phone number would be available to port IF you move your internet account. You could also ask if the VOIP package is independant of the Internet connection.

Brian