Fuel tanker drivers and their employers will try to resolve their dispute when they meet today.
Motorists across Wales are reporting regular but short term problems with buying petrol and diesel.
Protesters from across the country visit London today to call on the UK Government to cancel plans to increase fuel duty, and cut it instead
Customs officers have seized 2,800 litres of contaminated fuel, red diesel and kerosene from a filling station in Caerphilly.
Road fuel testing officers arriving at the site last Wednesday and found two large fuel tanks containing what claimed to be duty-paid white diesel selling at £1.25 a litre.
Checks showed the fuel contained large quantities of kerosene, which attracts a lower rate of duty. The kerosene had been added to white diesel in a process known as ‘stretching’.
Officers later seized and removed 990 litres of the contaminated fuel, 990 litres of red diesel and 820 litres of kerosene.
HM Revenue and Customs says as enquiries continued, a number of individuals arrived at the filling station to buy diesel.
Officers seized ten commercial and private vehicles which tested positive for red diesel or contaminated fuel. These were restored after payment of a penalty plus the duty on a full tank of white diesel.
Stuart Fenton from HMRC’s Road Fuel Testing Unit said, "White diesel selling at 15p less than the normal price might seem like a fantastic deal, but in this case it was no bargain. Kerosene makes white diesel more combustible, and prolonged use would undoubtedly damage the engine of any vehicle."
Investigations are continuing.
Latest figures from the AA show that unleaded petrol is up four pence per litre this month to 142.9, while diesel increased by 2.2p to 148.1.
This is the highest it has been since April 2011, when unleaded stood at 137.2p and diesel at 141.7p.
In the UK, the average cost of petrol has gone up to 142.48p a litre. Diesel, at 147.88p a litre on average, is just short of the record price which was set last week.
- Unleaded petrol stands at 142.9ppl
- Diesel stands at 148.1ppl
The union representing petrol tanker drivers has promised that there will be no strikes over Easter.
Despite the announcement, there's been little reduction in the numbers of motorists queuing at stations across Wales.
The massive increase in demand has led to another day of intermittent supplies.
ITV Wales has been to one forecourt which ran out of fuel first thing this morning.
The reason why they have run out is simply due to the fact that they have been unable to keep up with the demand, as people are panic buying over fears tanker drivers are to strike.
Normally this particular garage, in Cyncoed in Cardiff, sells 2000 litres of unleaded petrol everyday.
Yesterday they sold 15,000 and this garage isn't unique there is a similar story across the rest of the country.
A petrol station in Cardiff say they sold 15,000 litres of fuel yesterday. They would expect to sell 2,000 litres on a normal day. The garage ran out of fuel at 7:30 this morning.
The main union for tanker workers, Unite, has ruled out strike action by tanker drivers over Easter to focus on talks.
First Minister Carwyn Jones has today told the UK Government to calm down and to stop spreading panic over potential fuel shortages.
The First Minister used a press conference to assure people that the UK does have enough fuel.
North Wales Fire Service is warning people that storingpetrol or other fuels at home presents a potential hazard and should be avoideddue to the risks involved. The advice comes after the UK government encouraged people to stock up on petrol ahead of any potential strike by tanker drivers.
– Gary Brandrick, Senior Operations Manager North Wales Fire and Rescue
It is an offence to store more than the legal limit of fuel, unless you have a licence issued by the Petroleum Licensing Authority. Petrol is a dangerous substance which, when present can dramatically increase the risk of fire.”
Some petrol stations, including this one in Old Colwyn are restricting the amount of petrol and diesel that can bought to avoid running out of fuel. People are being urged not to panic buy, ahead of a potential tanker driver strike. No date has yet been set for any action.