New research suggests that packaging tobacco in plain packs reduces the likelihood of smokers seeking to obtain cigarettes.

Researchers at the University of Exeter found that compared to branded packs, plain tobacco packaging reduced the likelihood of smokers seeking to obtain cigarettes by almost 10 percent.

The findings come amidst debate over whether a law introducing plain cigarette packaging in England and Wales could come into force in 2016. Last month ministers said MPs would be asked to vote on the plan before May's general election, following a series of public consultations on the issue.

"In fact, the plain packs promoted no more tobacco choice than when nothing was presented," Lee Hogarth, lead author of the study, said in a statement. "These findings provide experimental support for the idea that introducing plain packaging might reduce tobacco purchasing or consumption."

In the experiments, researchers gave smokers the option to choose between pressing a key that might earn cigarettes or a key that might earn chocolate. Participants were uncertain about which key was most likely to pay off in each trial.

Just before participants made each choice, they were presented with either a picture of a branded cigarette pack, a picture of a plain cigarette pack, or nothing. The results showed that whereas branded packs increased the probability of participants making the cigarette choice by 10 percent compared to when nothing was presented, the plain packs did not. The implication is that plain packs are less effective at prompting smokers to purchase cigarettes compared to branded packs.

"Our study demonstrated that, under some circumstances, plain packaging can reduce cigarette-seeking behavior," Hogarth said. "Policy makers must consider how much weight to place on this observation when considering the potential pros and cons of introducing plain packing as a national policy".

The findings are detailed in the journal Addiction.