UK Working For a Foreign Company whilst Living in UK

[DTL]

Hi,

I am a UK resident.

I have been offered some work with a Mauritanian company, some of which I will perform from UK home office and some from site in Mauritania.
For all of the work I am told I will pay Mauritanian taxes and then gain a tax credit against UK tax for the taxes I paid to Mauritania.

I am aligned with the work that I will perform in person/physically in Mauritania, however the work I will perform in the UK confuses me WRT UK national insurance contributions;

If I am working in the UK am I not obliged to pay taxes via the PAYE system including UK national insurance?
Or does the fact that I am working for a Mauritanian company exclude me from UK PAYE and NI (although of course I pay UK taxes on my worldwide income)?

Thanks