New customers signing up for a super-fast BT Infinity broadband deal online can get their hands on a £125 Sainsbury's and £50 M&S voucher.
For a limited time only, the gift cards are available with a number of fibre broadband packages, including BT Infinity 1, Unlimited BT Infinity 1 and Unlimited BT Infinity 2.
Consumers in fibre-networked areas have a choice between up to 38Mb and 76Mb broadband deals.
BT's entry-level fibre option is BT Infinity 1, which offers up to 38Mb download speeds with a 20GB usage allowance, weekend calls and a Home Hub 5 router.
As with other BT broadband deals, extras such as free Wi-Fi access, cloud storage, BT Parental Controls, BT SmartTalk and access to BT Sport are included.
The broadband deal is initially priced at £7.50 per month plus line rental.
Households seeking unlimited downloads can enjoy the same deal - but with no restrictions on data consumption - for £10 per month plus line rental.
As with BT Infinity 1, a £30 activation charge applies to new fibre customers, although a line connection is included for those who need one.
The higher-tier super-fast broadband package is Unlimited BT Infinity 2, which offers up to 76Mb download speeds and up to 19Mb uploads, with no restrictions on data consumption.
Weekend calls, a Home Hub 5 and all the other fibre deal features are included, plus additional BT Cloud storage space (50GB).
Unlimited BT Infinity 2 is priced at £25 per month plus line rental over the course of a 12-month contract.
Consumers wanting to take advantage of the £125 Sainsbury's and £50 M&S voucher offer need to sign up for BT Infinity by Friday January 23rd.