The union representing fuel tanker drivers claimed today their working conditions had been "eroded", ahead of peace talks to avoid strike action.
The Unite union and fuel distributors are expected to meet later this week to resolve a threatened strike by tanker drivers, which prompted widespread panic buying of petrol and diesel.
The talks will come after the Government was forced to defend its handling of the threatened strike following fierce criticism.
Speaking to ITV's Daybreak, Unite's assistant general secretary Diana Holland said: "Everybody involved on behalf of Unite, the trade union members, and the oil tanker drivers, is saying we want a negotiated settlement. That won't happen without all parties coming together.
"This industry used to be one run by the oil companies alone. Over the years it's been contracted out to other companies and the conditions and the terms were kept pretty solidly at the beginning. But over the years they have become eroded and eroded."
She added: "This is not a new issue. We have been alerting the Government all the way along.
"The people that are on the best conditions, the best rates of pay and the best training - we want to keep that for them.
"We want to put a floor in, under which no-one can fall. When the contract negotiations take place, we want the oil companies, the retailers, and the distribution companies to say no-one will fall below this standard."
The latest Government advice to motorists is that there is "no urgency to top up your tank".
Downing Street said the advice had changed following Unite's statement confirming that it would not strike over Easter.
Asked if David Cameron had full confidence in Cabinet Minister Francis Maude following last week's panic buying, the Prime Minister's official spokesman said: "Yes."
When pressed over whether Mr Maude remained the lead minister dealing with the issue, the spokesman said he was "in charge" of the part of the Cabinet Office that deals with civil contingencies but the Department for Energy and Climate Change (DECC) was the "lead department".
No 10 urged motorists to check the DECC website for updates on its advice over petrol supplies.
It states today that motorists "can help by following sensible advice at this point, before there is a strike and when there is no problem with supply".
It suggests: "There is no need to queue at petrol forecourts.
"There is no urgency to top up your tank, a strike will not happen over Easter.
"Check travel sites and latest news before travelling.
"Stick to speed limits as this helps conserve fuel."
The advice is markedly toned down from last week's recommendation to keep tanks topped up and Mr Maude's suggestion to motorists to fill up jerry cans.
"What has changed here is that Unite has made clear that there will be no strikes before Easter," the spokesman said.
"You would expect this advice to reflect the latest situation and that's why people should refer to the DECC website."