The pressure put on the UK's energy supplies by the current cold weather with the arrival in port of a lhave easedarge gas tanker from Qatar. Another shipment is due on Monday and two more later in the week, assuaging concerns about Britain's depleting gas reserves.

As the unseasonal cold snap increased demand for heating and electricity, the government moved to reassure people that there would be no danger of shortages, and that the energy regulator and the National Grid are closely monitoring the situation. John Hayes, the energy minister, said: "The UK's gas needs continue to be met. We get our supplies from a diverse range of sources and the market is proving highly responsive to the UK's needs."

Concerns were raised on Thursday when it emerged that Britain only had enough gas in storage to meet two days' demand. As the UK receives gas from pipelines in mainland Europe, there was no immediate danger of running out, but the situation was growing tight.

Then on Friday, one of the key pipelines – from Belgium – was suddenly shut down after a component failed. The pipeline was back in operation later that afternoon, but not before gas had doubled in price on the UK's energy markets.

The price fell back again, leaving no lasting impact on consumer bills, but the incident highlighted Britain's dependence on imported gas. It also called into question the government's strategy of a "dash for gas" that would make the fuel more dominant in the energy mix.

Angela Knight, chief executive of Energy UK, the body that represents energy companies, said: "This focuses attention on energy security, and that is very important. We need to ensure that energy is secure and comes from a diverse mix of sources."

She said the three key aspects of energy policy were affordability, the reduction of carbon dioxide emissions and the security of supply, but that in recent years the latter had often been overlooked.

Hayes said the weekend shipment, combined with pipeline imports and North Sea production, supplied more gas than was needed. This surplus has enabled some storage sites to be replenished, cushioning demand in the coming days.

National Grid has not yet been obliged to use any of its emergency powers to cut gas to industry and redirect it to consumers. Ofgem, the energy regulator, said: "While gas supplies are tight at the moment and there is no room for complacency, Britain does benefit from a diverse range of gas supplies and National Grid has many tools to manage the system and to prevent householders' supplies from being disrupted."

Hayes said: "We are never complacent, but National Grid are confident that the situation is stable and as expected."

Green campaigners said that an over-reliance on gas was exposing households to volatile international markets in the fuel, and a dependence on imports that could easily be disrupted. Although the UK has built new infrastructure in recent years to increase the amount of liquefied natural gas that can be shipped and stored here, the supply from Qatar – the biggest exporter of the fuel – is likely to become more expensive as expanding developing economies soak up more of the available supply.