A tax on takeaway boxes is to be considered in an attempt to tackle the problem of plastic waste.
In Wednesday's Budget, Chancellor Philip Hammond is expected to call for evidence on whether a tax on the use of the most environmentally damaging single-use plastics would help.
Single-use plastics include packaging, bubble wrap, and polystyrene takeaway boxes.
Greenpeace said ocean plastic pollution was "a global emergency".
Meanwhile, Stephen Hammond, a close friend of the chancellor, has told the BBC the chancellor wants to use the Budget to "attack problems" that contributed to the Tories' poor election performance.
He plans to use "headroom" in the public finances to target spending on housing and health, the former transport minister told Newsnight.
The Treasury said the work on a potential plastic tax would examine the lifecycle of single-use plastics.
It did not suggest the investigation would include plastic bottles, which can be recycled, although in practice many also end up in land-fill or the sea.
However, the government has already said it would consider whether to introduce a "reward and return" scheme for plastic bottles to try to improve recycling rates.
The Treasury said the amount of single-use plastic wasted every year in the UK would fill London's Royal Albert Hall 1,000 times, and cited the success of the 5p charge on plastic bags to illustrate the feasibility of a levy.
Birds, sea mammals and turtles die from consuming or becoming tangled in plastic waste.
Sir David Attenborough recently described the "heartbreaking" sight of an albatross feeding plastic to its young chick instead of fish.
Sue Kinsey, senior pollution policy officer at the Marine Conservation Society, said plastic was a "complete menace" in the marine environment.
"It takes a long time to break down and it's almost indigestible if animals eat it.
"The real danger is that animals are starving to death with stomachs full of plastic."
Tisha Brown, oceans campaigner for Greenpeace UK, said the move "recognises the significance of the problem and the urgent need for a solution."
But shadow environment secretary Sue Hayman criticised the government for "warm words" on the environment while underfunding services and failing to enshrine EU protections in UK law.
She said: "While we support initiatives to decrease the use of non-recyclable materials, the slump in recycling figures and significant increase in litter and dumped rubbish under this government requires a far more strategic approach."
The call for evidence is expected to be launched in early 2018.Let's