Video report by ITV News Political Correspondent Paul Brand
Over six million UK broadband connections may not be up to minimum government download speeds, according to a new report.
The British Infrastructure Group of MPs, led by former Tory party chairman Grant Shapps, have called on communications regulator Ofcom to compensate families who do not get the internet speeds they pay for.
The group's report, entitled "Broadbad 2.0", which is backed by a group 57 cross-party MPs, found as many as 6.7 million UK broadband connections may not be receiving download speeds above the proposed minimum download speeds.
Less than half of all UK connections are thought not to receive superfast speeds of 24 Mb/s, according to the group's research.
Scotland had eight of the 20 worst performing constituencies, closely followed by Wales with seven.
Ross, Skye and Lochaber in Scotland is the worst area in the UK for broadband with around two thirds of internet connections failing to reach the government's proposed minimum standard.
The worst parliamentary constituencies for download speeds
Ross, Skye and Lochaber, Scotland 65.6
Na h-Eileanan an Iar, Scotland 63.7
Argyll and Bute, Scotland 61.7
Orkney and Shetland, Scotland 61.7
Carmarthen East and Dinefwr, Wales 58.2
Montgomeryshire, Wales 58
Kingston upon Hull East, Yorkshire and the Humber 56.8
Ceredigion, Wales 55.1
North Herefordshire, West Midlands 54.9
Caithness, Sutherland and Easter Ross, Scotland 52.2
Dwyfor Meirionnydd, Wales 50.9
Carmarthen West and South Pembrokeshire, Wales 49.8
Brecon and Radnorshire, Wales 48.9
Hereford and South Herefordshire, West Midlands 48.9
Carlisle, North West 48
Midlothian, Scotland 47.5
Inverness, Nairn, Badenoch and Strathspey, Scotland 47.3
Merthyr Tydfil and Rhymney, Wales 47.3
Dumfriesshire, Clydesdale and Tweeddale, Scotland 47
Central Devon, South West 46.8
Torridge and West Devon, South West 46.8
Ofcom has been urged to get tougher on broadband providers.
It previously found 1.4 million people have download speeds below 10 Mb/s, while the Department for Digital, Culture, Media and Sport (DCMS) said millions of people had not signed up to superfast broadband.
However, the MPs say data gathered by Ofcom does not distinguish between connections for customers not signed up to superfast broadband, and those customers not getting the speeds they are paying for.
Mr Shapps said: "It is unacceptable that there are still no minimum standards in the UK telecoms sector to protect customers from protracted complaints procedures, and ensure that broadband providers are fully accountable to their customers."
Ofcom said they provide "robust, comprehensive data on broadband take-up and availability".
The MPs also want Ofcom to produce better data on the take-up and availability of connections, and consider legal rather than voluntary codes of practice for internet providers.
Ofcom's voluntary code of practice with providers such as BT and Virgin Media commits them to provide accurate and transparent information on speeds, and allows customers to exit their contract without penalty if speeds fall below a minimum threshold.
An Ofcom spokesman said: "We share concerns that broadband must improve, and we're already taking firm, wide-ranging action to protect customers - including new plans for automatic compensation, faster repairs and installations, and ensuring providers commit to giving accurate speed information to customers."