Unable to keep landline, when joining Sky

[Rob0299]

I had agreed a deal to move from NowBroadband to Sky.  This was a phone broadband and tv package and I wanted to keep my landline number since I have a few elderly relatives who still use this to phone us.  

However I have just been told by sky that they cannot fulfill the contract due to not being able to keep my landline number.  It was my understanding that under Offcom rules, providers had to port over your landline when requested.  Is this wrong?  Does anyone have any tips?

[Mark39]

OFCOM don't insist on a number being ported where Sky or the previous provider claim technical difficulty in doing so.

Sky acknowledge the possibility in their help guide here: https://www.sky.com/help/articles/switching-broadband-provider-switch-to-sky