TalkTalk Mobile has unveiled what it claims to be the cheapest SIM-only mobile price plan in the UK. For just £3.50 a month on a 12-month contract, you get 100 minutes of talk time, 250 texts and 100MB of data. And if you buy from TalkTalk's online store, you get double data - giving you 200MB a month instead.

In addition, the network has rejigged its existing Medium and Large tariffs. It has increased the amount of minutes and texts each plan comes with. The Medium tariff now offers 500 minutes of talk time and unlimited texts. You also get 1GB of data if you buy online. This can cost from £7.50 a month for 12 months on a SIM-only plan.

The Large tariff now offers unlimited minutes and texts, with 4GB of data with the online double data incentive. SIM-only for 12 months will set you back from £15 a month.

TalkTalk also offers deals with handsets.

"Our new tariffs are centred around having more time to chat, text and surf the net without paying a penny extra,"  said Dan Meader, mobile director at TalkTalk.

"With more handsets than people out there, our SIM-only price plans are perfect for people who want to keep their current handset or hand it down to their children, without having to take a pricey contract. We want people to have more choice and flexibility."