An energy minister has refused to rule out a rise in fuel duties following a drop in oil prices.

Baroness Verma, the Department for Energy and Climate Change minister in the House of Lords, said green issues had to be considered.

Her comments came after Tory Lord Howell of Guildford, the father-in-law of Chancellor George Osborne, urged her to rule out any hikes.

Mr Osborne scrapped the fuel duty escalator, which meant petrol taxes rising by 1p a litre above inflation, in 2011, but said he would restore it if the price of a barrel fell below 75 US dollars.

Oil has plummeted to around 50 dollars a barrel, but Lord Howell called for the Government to resist upping taxes.

He asked Lady Verma at question time in the Lords: "As and when energy bills and heating bills and so on do fall because of far lower crude oil prices and gas prices, will you reject the idea that taxes and charges and green levies should be piled on to push the price up again?"

She replied: "We do need to look at the impact of all polices. This is what this Government has done.

"It has carefully looked at and responded to any negative impact of our policies. If we are to ensure that we move towards a cleaner environment, then some of those policies have to be met."

Edmund King, president of motoring organisation the AA, said: "The Chancellor scrapped the fuel duty escalator because spikes in the pump price were helping to break family budgets. The knock-on effect of that was to cut spending and undermine the high street and economy.

"AA Populus surveys of around 20,000 AA members consistently showed that lower-skilled and lower-income workers, youngsters having to travel to find their first jobs, and pensioners whose savings' income had been slashed by the financial crisis suffered most.

"Higher-cost fuel, pumped up by increased VAT, effectively became a tax on the less well-off."

"Fuel duty increases and the trauma of pump price spikes over the past seven years continue to cast a shadow - the recent collapse in pump prices has yet to trigger a resurgence in car use.

"Against that backdrop, in an election year, the party that supports an increase in fuel duty is asking for a backlash at the ballot box."

A spokesman for the Department of Energy and Climate Change said: "Baroness Verma did not suggest fuel duty would rise, but that the Government had carefully considered the impact of all its policies. Fuel duty is a matter for HM Treasury."