Can I travel whilst my Tier 2 extension is decided?

[Viralts]

My Tier 2 sponsored visa will expire in August - I obtained this using Passport A

If i send in an extension application, and whilst it is being decided, want to travel on Passport B - am I allowed?

Will this confuse the immigration department, if I use Passport B to enter the country and then just stay on this passport? Technically I am resident for tax purposes, and (when the extension is processed) will receive both my other passport and the biometric permit so am allowed to work and live here?

And another unrelated question - is my BRP linked to my passport? i.e. do i need to update UKBA if I renew my passport A? I am getting it renewed soon too.

[Viralts]

Can anyone help?

Thanks!

[Apam]

In theory this should be possible to travel on anther passport and re-enter the UK if you are not a visa national.
I'm tempted to say, don't take any changes with immigration issues otherwise it might cost you in future.
Ukba may want to contact you during your extension application for anything at all , if you are out of the country may go against you.
Also they clearly advice you not to make any travel arrangements until you receive your brp.
A bit of patience always pays.

[FaeLLe]

You can request for your passport while a decision is being made (for exceptional circumstances).
However, if you travel the application will be cancelled / withdrawn and a new application will need to be made.

For reference refer to the Tier 2 Policy guidelines.