Poland says it is planning to build a wall to stop migrants crossing the border into Belarus, according to a draft law due to be debated in parliament on Wednesday.

The wall is estimated to cost 353 million euros ($407 million) to construct and will include motion detectors.

The cabinet adopted the draft on Tuesday and it is due to be voted by lawmakers later on Wednesday or on Thursday.

"The number of attempts to cross the border is growing," the government said in the justification for the legislation.

The draft law also states that the public may not be allowed within 200 metres (656 feet) of the barrier.

Thousands of migrants -- mostly from the Middle East and Africa -- have tried to cross the Polish border from Belarus since August.

The EU has said the influx has been deliberately engineered by the Belarusian regime as a way of retaliating against EU sanctions.

Poland has responded to the unprecedented migrant arrivals by sending thousands of soldiers to the border and implementing a state of emergency there, as well as building a razor-wire fence.

Poland was one of 12 member states that last week asked the EU to pay for border "barriers" to stop migrants from entering.

The plans for the wall were immediately criticised by non-governmental organisations, which have accused the Polish government of a heavy-handed response to the migrant influx and have warned of increasingly dangerous conditions.

The state of emergency, which prevents journalists and charity workers from going near the frontier, has proved particularly controversial and the EU has called for "transparency".