A Labour candidate has been accused of running a "dishonest and dangerous" campaign to woo Arab voters in her constituency, by playing up her support for the people of Gaza and misrepresenting her opposition to the war in Iraq.

Karen Buck, Labour's candidate in the newly-formed constituency of Westminster North, sent out a letter in Arabic to residents condemning the "collective punishment" of Palestinians in Gaza and describing the situation as "abhorrent".

The same letter contains the claim that she voted against the Iraq war. In fact, she abstained in the main vote that took Britain to war. A separate letter in English uses more moderate language about the conflict, emphasising instead, the resilience of the people of Gaza. The English version makes no mention of the Iraq war claim.

Ms Buck is fighting for her political life in Westminster North. Her Conservative opponent, barrister Joanne Cash, has been identified as a rising star and a future Cabinet prospect.

On her official website Ms Buck defends her claim that she opposed the war by pointing out that she voted for an amendment proposed by the Labour MP Peter Kilfoyle, which stated that the case for war had not been established.

The amendment was defeated and Ms Buck absented herself during the main vote that committed Britain's armed forces to the conflict.

"Karen Buck has shown herself to be dishonest and dangerous," said Ms Cash . "How could people trust someone who is prepared to lie about something so important to manipulate and patronise one community while betraying another? The people of Westminster North deserve better."

Ms Buck defended her anti-war credentials: "I clearly voted against the government on at least two occasions over Iraq including the Kilfoyle amendment." She added that she had championed the cause of Jewish voters.