Northern Ireland introduces their own 5p tax in April. Will Cameron tell retailers to bag it?
Cameron is known to want to but Chancellor George Osborne is known to be less supportive, worried the charge will be passed onto consumers when wages are already under pressure.
If the Government lacks the nerve to introduce it, England - the Scots are consulting on the issue - risks being the only part of the UK where single-use plastic bags are often routinely free.
The UK Carrier Bag Consortium, made up of plastic bag suppliers, is vehemently opposed to a tax, claiming it would wreck jobs and businesses "and do no good for the environment".
1 trillion a yearThat view is looking increasingly out of step with public support on the issue. The US Environmental Protection Agency claims that worldwide between 500 billion and one trillion plastic bags are used every year.
In parts of the North Pacific fishing boat nets now trap more plastic - in terms of weight - than fish. See Charting the garbage patches of the sea. (There's concern plastic toxins are entering the food chain as fish nibble on tiny pieces of plastic floating in the sea.)
Back at home, it's estimated UK supermarkets continue to dispense around 6bn plastic bags a year with each bag taking around 1,000 years to fully biodegrade. Although some feel the Government continues to dither on the issue, the move is thought to be supported by environment minister, David Heath.
Environment vs TreasurySpurred by their recent by-election victory in Eastleigh, the Lib Dems hope to apply more pressure on the Tories to adopt the move. A Defra spokesperson told AOL Money: "Our position remains the same; a decision on a charge has yet to be made. We continue to monitor the situation in Wales, Scotland and NI and we are considering all the relevant factors, including the pressure on household budgets at this time."
The Campaign to Protect Rural England, Keep Britain Tidy, the Marine Conservation Society and Surfers Against Sewage have launched the Break the Bag Habit campaign, encouraging people to write to their MP to support the tax.