Gordon Brown insisted today his action plan for tackling the financial crisis would work - despite renewed turmoil on global markets.
The Prime Minister said "hard-working families" in the UK would start to feel the benefit of efforts to bring down oil prices and ease the cost of borrowing.
But he also hit out at some retailers for failing to pass on lower oil prices at the petrol pumps quickly.
Speaking after the conclusion of a summit of EU leaders in Brussels, Mr Brown identified fuel costs and mortgage rates as key areas.
"These are the issues that we are working on every day and I believe that we will see changes as a result of the measures we are working on," he said.
Mr Brown said he was pleased that some British supermarkets have dropped petrol prices below £1 a litre, after oil costs fell to around 80 US dollars a barrel.
"But I would like to see other retailers folllowing that lead," he said. "The average price is still £1.07 and there is still too much variation of price across our country.
"In some areas, the petrol price is still as much as £1.20 a litre. That must change."
The Prime Minister defended the Government's decision to increase its borrowing to stave off a deep recession and ease pressure on families.
"We have said that because we have got low national debt, we are in a position to borrow to keep the economy moving forward," he said.
Asked about another slide on global markets - with dramatic drops of up to 11% in Asia overnight driving the FTSE down more than 100 points today - Mr Brown stressed international action had to be given time to take effect.
"I think the markets are reflecting not just events in our country but what is happening in every part of the world," he said.
"There will be uncertainty until we finalise many of the decisions that have been made in other countries at other times."
He went on: "The issue for me is what we can do to help hardworking families in our country - what we can do to help people facing high petrol prices high gas and electricity bills, people seeking mortgages and small businesses worried about their cashflows."
Mr Brown batted away questions over whether he might call a snap general election, to take advantage of public perception that he is handling the financial crisis well.
"I am getting on with the job and trying to get us through these difficult times. It has got my undivided attention."
Pressed again on the issue later in the press conference, he added: "I will take the British people through these difficulties and help pensioners facing fuel bills with higher allowances than last year, and help with special tariffs for gas and electricity for those on low incomes.
"That's the only thing that is in my mind. I see it as my job to calm things down."