Britain’s nuclear weapons system Trident is being fiercely debated in the ongoing general election campaign, not least because the increasingly popular Scottish National Party has made it a red line issue for supporting a minority Labour government.

But its prominence also results from the fact that public opinion has shifted significantly against nuclear weapons over the past decade. This opposition currently centres on government plans to replace Trident – with a decision due by parliament in 2016.

Some have concerns about the legal and moral questions associated with these weapons of mass destruction – others now conclude that nuclear weapons are irrelevant to our security needs.

But the price tag of more than £100 billion (US$150bn) at a time of deep and unpopular spending cuts is probably the most significant factor in explaining this popular hostility.

There are many areas where this money could be more usefully spent – and is urgently needed - to sustain the well-being of the population.

Even though Britain is one of the richest countries in the world, many are currently struggling to eat and keep warm.

Hundreds of thousands of people now rely on food banks, a damning indictment of the government’s priorities. In a letter to the British Medical Journal in 2013, a group of health experts warned that food poverty should be seen as a ‘public health emergency’. Malnutrition can lead to severe health problems, which costs the National Health Service at least £4 billion each year (US$6bn). It is clear that the government could save billions by tackling preventable diseases caused by food poverty.

The Trussell Trust, which runs 400 food banks across the UK, is now helping 350,000 people. It is estimated by Oxfam and Church Action on Poverty that over half a million people in total rely on food parcels. It is estimated that the average cost of running a food bank for 3,000 people is around £14,000 (US21,000). A small proportion of the cost of replacing Trident could run thousands of food banks in the UK.

The increasing number of people in poverty follows drastic cuts in the government’s welfare payments. The changes in repayable crisis loans, increased conditionality on benefit payments and reassessments are just some of the measures which have affected low-income families. The ‘bedroom tax’ and the introduction of universal credit will affect many more.

There are 3.5 million children growing up in poverty today including in households where adults are working. Too many people are trapped in part-time work or earning the minimum wage, which is not high enough. The cost of living is rising far higher than wages and welfare payments. Cancelling Trident replacement would save the government twenty times more money than saved by its reforms to tax credits.

Cold weather kills around 20,000 people in the UK each year. Thousands more suffer in cold homes as they can’t afford to turn on the heating. And yet the government is reducing its spending on fuel poverty. The campaigning group Energy Bill Revolution is calling for a new energy efficiency programme which could remove the vast majority of fuel poor households from fuel poverty. £4 billion (US$6bn) a year is needed to adapt 600,000 homes a year. The £100 billion spent on Trident would pay to insulate over 15 million households.

This investment would also create jobs as well as ending fuel poverty and bringing down energy bills. 

Alternatively, investment in key sectors can create employment as well as addressing important issues such as climate change. This is a serious problem with potentially devastating consequences for our communities. Britain is committed to reducing its carbon emissions in order to avoid dangerous climate change. Investing in energy efficiency measures and developing renewable energy are the best ways to do this.

Producing our own energy from solar, wind and hydro sources also increases our energy security and creates jobs for thousands of workers. The UK has more than enough wind and tidal power to meet our energy needs, but investment is needed. 100,000 wind turbines could be built if the money spent on replacing Trident was invested in renewable energy. This is enough to power all the households in the United Kingdom, as well as generating some excess energy which could be exported for profit.

Alternatively, at an average cost of £6,500 (US$9,000) to install per household, solar panels produce clean energy and bring bills down. £100 billion could pay for 15 million households to have solar panels fitted, almost 60% of all households in the UK. It is estimated that having solar panels fitted saves the average household £800 a year (US$1,200).

The renewable energy sector could potentially employ highly-skilled engineers who would otherwise be working on Trident replacement. Instead of investing in a weapon of mass destruction, the government could spend the money on developing renewable energy, making Britain a world leader in this new technology.

In view of the many and varied ways in which this money could be spent to the benefit of all, it is easy to see why so many people now question the wisdom of spending vast sums on a Cold War weapons system.

As the new parliament assembles in May, this is a subject they will have to address fairly rapidly, so this is clearly an issue that will remain at the top of the political agenda for some time to come.

• Dr Kate Hudson is the General Secretary of the UK Campaign for Nuclear Disarmament.