Pizza Express decided to stop using plastic straws after receiving an adorable letter from a five-year-old concerned about the environmental impact on animals.

The popular Italian chain announced on Thursday (25 January) that it will begin phasing out single-use plastic straws and replace them with biodegradable and recyclable paper ones, after a handwritten letter from a young girl called Ava who highlighted that they are "very bad for animals".

Ava wrote: "I am writing because me and my brothers eat in Pizza Express a lot. When I get my drink it always has a plastic straw in it.

"I am writing to please ask you to stop using plastic straws as they are very bad for animals. They can get stuck in their mouths and noses. Could you only use straws if people ask for them as I don't want any animals to get sick."

Pizza Express said the letter had acted as a catalyst for change, although they did not reference Ava's request to only give out straws if people ask for them.

In a statement posted on Facebook, the popular chain wrote: "We pride ourselves on listening to our customers, so when Ava, aged five, sent us a letter asking us to stop putting plastic straws in her drink because "they are very bad for animals.", it spurred us to make a change.

"We are now phasing out single-use plastic straws from all our 470+ restaurants from this summer, and we'll be replacing them with biodegradable and recyclable paper versions."

Responding to accusations that the letter was just a PR stunt, or even a pushy mother forcing her daughter to write the letter to try and get a free meal, a Pizza Express spokesperson added: "For the record, Ava's letter is genuine and it's truly amazing and wonderful that somebody so young wrote to us with such a caring and compassionate message."

Some 70 million plastic straws end up in landfills or the ocean every year, and then into the bodies of animals, with whole straws even found inside the nostrils of turtles. It takes around 500 years for a single plastic straw to decompose.

Costa Coffee, Wagamama, Leon, Bill's, Wahaca, Franco Manca, Pizza Pilgrims and Pret A Manger have all recently made the same commitment to stop using disposable plastic straws.