Despite widespread coverage and fast download speeds, mobile companies EE and Vodafone have been voted the two worst providers in an annual customer satisfaction survey.

According to the poll carried out by consumer group Which?, only one in five EE customers would definitely recommend the company, while just a quarter would recommend Vodafone.

The two achieved a score of 50% in the poll based on more than 4,000 customers' experiences.

Smaller providers Giffgaff and Utility Warehouse topped the survey table with scores of 81% and 76% respectively.

Alex Neill of Which? said: "Year after year we see the smaller providers giving great service and some of the biggest providers struggling to meet their customers' expectations.

"Those who are fed up of receiving a poor service from their provider should look to switch."

Mobile providers as ranked according to the Which? customer survey are:

Giffgaff (81%)

Utility Warehouse (76%)

Tesco Mobile (74%)

Asda Mobile (72%)

Talkmobile (69%)

Plusnet (66%)

3 (Three) (64%)

iD (Carphone Warehouse) (63%)

BT Mobile (63%)

O2 (62%)

TalkTalk Mobile (62%); Virgin Mobile (62%)

EE (50%); Vodafone (50%)

Smaller network providers scored better for customer experience Credit: PA

Over the last 12 months both EE and Vodafone have found themselves in trouble with the regulator.

EE was fined £2.7 million by Ofcom in January after the regulator found the company twice broke a "fundamental billing rule", resulting in nearly 40,000 customers being overcharged around £250,000.

In October last year, Ofcom fined Vodafone £4.6 million as a result of two investigations which found the company was mishandling customer complaints and failed to credit the accounts of more than 10,452 pay-as-you-go customers who topped up their accounts.

Both providers committed to making improvements following the issues.

Responding to the survey, a Vodafone spokeswoman acknowledged that 2016 had been a "difficult year" but said that improvements had already been made and that improving customer servies was a "top priotiry".

EE said: "Getting a good 4G connection is one of the most important factors for consumers, so it's disappointing that these ratings don't take network performance into account.

"Which?'s own report shows that only EE customers get the fastest 4G connection in the UK, and are on 4G more of the time than any other network. The latest data from Ofcom shows that EE has improved customer service and receives the third fewest complaints in the mobile industry."

Last week Ofcom announced plans for a "text-to-switch" scheme to allow customers to move to a new network within 24 hours and prevent awkward phone calls to the company people wanted to leave.