The row over the contentious Western Harbour Crossing surcharge could provoke a strike if the affair is unresolved, rival taxi unions said yesterday. Several associations petitioned the Transport Advisory Committee calling for negotiations to increase the proposed $40 surcharge to $60. But unions are at odds about a strike call should talks fail. Drivers said they stood to lose business under the proposal which would force them to return to home districts via the two cheaper existing tunnels. Cheng Man-kit, vice-chairman of the Urban Taxi Drivers' Association, said the proposal would cause congestion. 'Drivers would have no choice but to use the two old tunnels again because fees are lower. 'What's the point of constructing the Western Harbour Tunnel if it cannot solve congestion?' Mr Cheng asked. He said drivers might initiate a strike if negotiations broke down. But other unions argued a strike was too radical and would further hurt business, already on a downward trend this year. A Transport Branch spokesman said the Government was confident a $40 fee was acceptable to the public. The Transport Department has contingency measures to bolster other transport in the event of a strike.