By Judith Townend

It was easy for me to put my questions directly to the Brighton Pavilion candidates because they've been fighting it out on Twitter. I didn't even need to leave the house. My most pressing question concerns child detention. I've been involved in a citizens' campaign to end the detention of children by UK immigration authorities.

Gordon Brown’s government has locked up 2,000 children every year just because their parents are asylum seekers. But even the Home Office admits asylum seekers with children don’t abscond and doctors say detention causes children terrible psychological harm.

Our campaign has received support from all quarters: from authors to actors to religious leaders. The Liberal Democrats are the only of the three main parties that pledged to end this practice in its manifesto. In some constituencies, like those in Hackney, the issue has caused significant political rupture - even within the same party.

As it's an issue that causes disagreement within parties, I wanted to know what each of the four main candidates - in the hotly contested Brighton Pavilion seat - thought.

First to reply was the Greens' Caroline Lucas (@carolinelucas): Greens absolutely oppose child detention. I've been active in campaign to close Yarl's Wood - locking up children is shameful Then Labour's Nancy Platts (@nancy4brighton): I oppose child detention & fully support your campaign.

Finally, Lib Dem candidate Bernadette Millam, via email: "I do not want to see one child in detention (...) I will do my best to protect children elected or not."

I'm yet to hear back from Conservative candidate Charlotte Vere, despite sending numerous tweets and an email linking to the End Child Dentention Now campaign. (I'm still waiting and would be glad to update this post, if she gets in touch).

On Monday at the Citizens UK event, the party leaders faced the same question over child detention. Labour leader Gordon Brown, forced to answer when publicly heckled, did not commit his support. Nor did the Conservatives' Cameron, who said he would "look at this issue and see how we can change it”. It was left for Liberal Democrat leader Clegg to denounce child detention entirely: “No, we shouldn’t be locking up children, under-age children in 21st century Britain”.

I'm pleased that three of the leading Brighton Pavilion candidates have been more forthcoming than their leaders and, even better, pledged to end the imprisonment of children in immigration centres such as Yarl's Wood.

To read more about our campaign and about the alternatives to child detention visit A no. 10 online petition will re-open once the election is over.