The work measuring 50 metres (164 feet) long depicts a smiling girl cradling the Earth and beside it are the words: "Vote for Climate, Vote for Our Future".

Artist Jamie Wardley, who created the painting for Earth Day on Monday, hopes the message will remind voters to consider the environment when they cast their ballots in a UK general election due this year.

Wardley, who used football pitch paint and sprayers to create the painting, said the election was an opportunity for voters to prioritise the environment, which was why the work was hopeful in tone.

"She's optimistic because this year it's the UK elections, and it's a chance for us to make a real difference for our children's future," he told AFP.

"It's only governments that can set policies and regulations that make a significant difference," he added.

It took a team of 10 artists three days to complete the painting and Wardley's daughter was used as the model.

"It survived the rain a bit, and it'll be here for probably another week," Wardley said.

"This isn't going to change the world, but it might help a little. And if we all pitch in, then hopefully we make a difference."

Earth Day is observed annually on April 22. First celebrated in 1970, it now includes a wide range of events across more than 193 countries, demonstrating support for environmental protection.