Nearly a fifth of London restaurant-goers have complained meals have been “ruined” by poor mobile reception stopping them posting pictures on Instagram, according to a survey.

The poll found that ever-increasing numbers of diners now routinely take photos and videos when sitting down to a meal out, even in the most exclusive West End restaurants.

Almost a third take pictures and a fifth record videos, mostly to be shared with followers on social media.

The practice is now so ingrained — with hashtags such as #foodie and #foodporn amassing hundreds of millions of posts on Instagram — that nearly one in seven choose their restaurants by how Instagram-able it is.

But there is also huge frustration with the quality of signal in many top restaurants with 26 per cent claiming that they have been unable to connect using mobile data when dining, and 28 per cent frustrated at slow speeds.

Astonishingly, 13 per cent said they would refuse to even order if they could not get access to their network through their phones.

The research by wireless analysts Global Wireless Solutions named Chojo in Notting Hill, Berners Tavern in Fitzrovia and Bourne & Hollingsworth Buildings in Clerkenwell as the highest ranked for web connection out of central London’s 50 most photogenic restaurants.

Eateries just outside West End W1 postcodes performed better and the most reliable networks were O2 and Vodafone. Although most restaurants offer WiFi, 29 per cent of diners said they had been unable to connect. One in eight said they would not tip if staff did not know the WiFi details.

Dr Paul Carter, chief executive of GWS, said: “If the network is slow and unreliable… that doesn’t bode well for the hipster chic restaurants”.