A Legislative Council by-election will have to be fought after a May poll result was ruled invalid yesterday. Dr Tang Siu-tong was stripped of his Regional Council functional constituency seat when Mr Justice Nicholas Barnett declared invalid three of the ballots cast in the Regional Council Functional Constituency race. The invalid papers had been marked with a tick, rather than numbers reflecting voter preferences. Two had been in Dr Tang's favour, securing his win, 25 votes to 24, over independent Ann Chiang Lai-wan. The third invalid vote was for Ms Chiang, so the result was amended to a tie. Dr Tang, of the Hong Kong Progressive Alliance, said outside court he was 'a little bit disappointed' with the ruling because he believed the voters' intentions had been clear. 'It is only on a technicality that I have lost,' he said. Mr Justice Barnett urged the Government to resolve contradictions in election rules. A set of unofficial guidelines, cleared by the Secretary for Justice and issued by the Chief Electoral Officer, were 'materially at variance with official guidelines issued by the [Electoral Affairs] Commission, apparently in conflict with the regulations, and inconsistent among themselves,' he said. 'I express hope that before the next elections, the authors of the guidelines will have put their heads together so as to produce, after taking account of this judgment, guidelines which are both consistent and which accurately reflect the law.' Ms Chiang had challenged the result in the Court of First Instance, arguing that she should have won as five of the 50 votes cast were invalid. Four of the five were for Dr Tang. Mr Justice Barnett accepted her argument that the three votes marked with a tick were invalid. But two others, inadvertently submitted with the number still attached, were ruled valid. A by-election could be held at the end of next month at the earliest, a spokesman for the Constitutional Affairs Bureau said. Ms Chiang said procedures should be speeded up to have a new legislator in place by early next month. 'They can announce the by-election procedures on Monday, give three days for nominations, seven more days for campaigning and vote,' she said. 'Everything could be done within a month and the new legislator could actually work on October 1.' The bureau spokesman said the end of October would be the earliest date, considering the by-election procedures. The notice to declare the vacancy in the Legco could be gazetted next Friday at the earliest.