Grocery giants Morrisons and Waitrose have launched fresh crackdowns on plastic packaging as they bid to tackle pollution.

Morrisons is to trial large paper bags for groceries, costing 20p each, and will also raise the price of its cheapest plastic bags from 10p to 15p.

The Bradford-based grocer said the recyclable and reusable paper bags would initially be introduced to eight of its stores as a result of consumer demand.

Supermarkets in Camden and Wood Green in London, Skipton, Hunslet and Yeadon in Yorkshire, Erskine in Scotland, Abergavenny in Wales, and Gibraltar will be the first to offer the new paper bags.

Morrisons customer and marketing director Andy Atkinson said: “These new paper bags do exactly the same job as standard plastic carrier bags. They are tough, reusable and can help keep a large amount of plastic out of the environment.”

Julian Kirby, waste and resources campaigner at Friends of the Earth, told The Guardian: “We welcome this – especially if they scale up from a trial. What stands out is that the bags are designed to be reused and will be less resource-intensive to produce than the heavier-duty tote bags and fully recyclable.”

According to government figures released last year, the number of single-use plastic carrier bags sold per year by Tesco, Sainsbury’s, Morrisons, Asda, M&S, the Co-op and Waitrose dropped to just over one billion. That number stood at more than seven billion in 2015, before the 5p plastic bag levy was introduced.

Separately, Waitrose & Partners has launched a new £1m grant fund, which uses cash from the sale of plastic bags for projects that help cut down on plastic packaging and pollution.

The scheme, titled Plan Plastic – The Million Pound Challenge, will award cash to projects that can positively impact plastic pollution now and in the future.

Waitrose is partnering with environmental charity Hubbub to support the chosen projects and measure the impact of the grants it will award over the next year.

Grants from the £1m fund will range from £150,000 to £300,000.

Waitrose’s head of CSR, health and agriculture Tor Harris said: We hope the fund will help find new and effective ways of accelerating action to rethink how we all use and dispose of plastic – now and in the future.

“We take this issue very seriously, and are making progress all the time, but we’re determined to maintain our momentum as well as supporting others to do the same.”