20 Feb 2017 - Surfers Against Sewage's (SAS) Message in A Bottle campaign is expected to pass the 250,000 milestone by the time it is discussed in the UK Parliament in May.
Hugo Tagholm, chief executive officer of the St Agnes-based charity said the fight to see an end to marine plastic pollution must go on.
He said: "The idea of the campaign is to trap plastic bottles in the economy not in the ocean."
SAS has been lobbying MPs, the Government and Department for the Environment, Food and Rural Affairs (Defra) to impose a 20p refundable levy on all plastic bottles to encourage users to return them to shops to go back into the drinks industry. The charity believes this could remove 40% of marine plastic litter.
The campaigners said the levy - when not refunded - would generate a surplus to pay for itself.
While all kinds of animals that feed on plankton also unintentionally ingest microplastic, birds and turtles often deliberately eat pieces of plastic which they mistake for food.
Many of the indigestible pieces cannot be excreted, leading to the animals starving with full stomachs, choking or suffering internal injuries.
Mr Tagholm said: "The campaign is a key focus for us at the moment and it will be heard in the House of Commons in May. We're obviously really please that so many people supporting our campaign to stop marine plastic pollution and our common sense approach of the deposit return system on plastic bottles we advocate."
He believed the levy would ensure consumers kept their single-use plastic bottles and drinks containers in the recycling economy and encourage manufacturers to opt for higher grade plastic bottles which would make sense to return and recycle. Other companies might also look to return to glass containers or biodegradable plastic for their bottles.
SAS wants the levy to have the same impact as the 5p charge on plastic bags, which has led to the number of single-use bags handed out drop by 83% to 500 million in the first six months, compared with seven billion the previous year. According to Defra figures, the charge also triggered donations of more than £29 million from retailers towards good causes including charities and community groups.
The charity has also been working with Ecovert for its annual Big Spring Beach Clean, the biggest beach clean project in the UK, with tens of thousands of volunteers participating over the past five years.
Mr Tagholm said the Big Spring Beach Clean will help remove 50,000 plastic bottles from UK beaches, recycling many into reusable, refillable Ecover Ocean Plastic Bottles in 2018. The event runs from April 3 to 9.