Rachel Reeves has been criticized over a “missed opportunity” to raise £900m [$1.17b] from online casinos in her first budget as chancellor, amid concerns about the Labour party’s ties to the £11bn-a-year gambling sector.

Both the Liberal Democrats and Derek Webb – one of Labour’s largest donors – questioned the chancellor’s rejection of proposals to double remote gaming duty (RGD), levied on online games of chance, from 21% to 42%.

The policy, initially proposed by the Social Market Foundation (SMF) thinktank, was among measures under consideration by Treasury officials. It also had support from the Liberal Democrats, who wanted to use the money raised – estimated at up to £900m – to fund health and social care.