Smoking rates are highest in low socioeconomic groups in the UK and a significant cause of poor health of children living in poverty. This is both as a result of exposure to passive smoke, and due to the increased likelihood that children who grow up in smoking households will become smokers themselves.

Parental smoking places a significant health burden on children. This in itself provides an argument for government intervention to reduce adult smoking. However, we also know that smoking is expensive, with a 20 pack of Marlboro Red costing in the region of £9.

The poverty threshold income level for a two parent household with two children is £392. If both parents are smokers, households could easily spend an average of £50 on tobacco per week, which is a big drain on an already tight budget in low income households.

My colleagues, from the UK Centre for Tobacco and Alcohol Studies, and I estimated to what extent smoking exacerbates childhood deprivation.

Our research suggests that over a million of the 2.3 million children currently living in poor households in the UK live with at least one adult that smokes. A further 400,000 children living in households with incomes just above the poverty line are drawn into relative poverty by parental expenditure on tobacco.

Children in poverty are more likely to live in inadequate housing and in more deprived communities, be exposed to high levels of air pollution, have a poor diet, develop depression and other long term health problems, and to be absent from school. Parental smoking increases the financial burden and almost certainly makes all of these problems worse.

It is clear from our estimates that smoking significantly reduces the income available for families to feed, clothe and otherwise care for large numbers of children living in low-income households.

The full implications of our findings are not yet clear; we are planning further research to find out what people in these households forego to pay for tobacco. Is it healthy food or just food in general; or keeping the house warm, or warm clothing?

Research has already shown that most smokers want to quit, but need help to do so.

What is clear is that if the government and our health services prioritize providing accessible individual-level smoking cessation support it could have a major effect on child poverty as well as mitigating the direct health impacts of parental smoking.