The Royal College of Physicians has called on the Government to introduce a 20% tax on sugar sweetened drinks, including sports drinks, in the Budget to tackle obesity.

One in four Irish children is classified as overweight or obese and doctors say sugary foods and drinks are a big part of the problem.

Professor Donal O'Shea of St Vincent's Hospital said the RCPI believes the tax would significantly impact childhood obesity and in time adult obesity.

"We simply have to act, obesity is killing 6,000 people a year in Ireland," Prof O'Shea said.

He said the best way to impact the consumption of "free sugar" is to target sugar-sweetened drinks.

Prof O'Shea said a number of measures are needed together to tackle the problem of obesity in the population.

"Simply taxing sugar sweetened drinks without education won't work," he said.

But doing nothing "is not an option", he added.

Research commissioned by the Department of Health has estimated that a 10% tax on sugary drinks would reduce the number of obese adults by 10,000.

The study is currently being examined by health experts, who will suggest a range of measures to be introduced by the Government.

The Irish Heart Foundation has also backed calls for tax hikes on sugary foods.

The Department said its budgetary proposals have not yet been finalised.

However, business leaders say increasing taxes will not solve the problem and would be damaging to foreign direct investment and put jobs at risk.

Fergal O'Brien from Ibec said that Irish households are already "taxed to the hilt".

"If we put more taxes on hard-pressed consumers it's going to result in more pressure for them," Mr O'Brien said.

"We are not going to get the change in consumption behaviour that Government and policymakers might desire. We'd see an increase in cross-border shopping. We'd see a loss in revenue, a loss in jobs to the State."