Campaigners are urging drivers to take the long way round

The Mersey Tunnel Users Association (MTUA) describes the proposal, which is being considered by the House of Lords, as a "tax on people going to work".

If the Mersey Tunnels Bill is passed, owners Merseytravel could increase tolls and use profits elsewhere.

MTUA said the tunnels will not be improved, even though Merseytravel say extra profits would be used for this.

Previously MTUA, who are not allied to any political party, said the bill would turn the River Mersey into a "psychological and economic Berlin Wall".

European standards

"It will hit the least well-off motorists hardest as an indiscriminate tax that falls equally on the rich and the poor," a spokesman said earlier this month.

"If the Bill is not stopped Merseyside will become unique in Britain, outside London."

Lord Hunt of Wirral is supporting the campaigners, saying original legislation promised tolls would be reduced or stopped once tunnel construction costs had been covered.

However, supporters of the bill say the revenue would help bring the tunnels up to European safety standards.