And they have the full backing of the loyal orders.

Police commanders are determined to ensure that street by-laws prohibiting the consumption of alcohol in designated public places are enforced right across the province on Thursday.

In recent years, police have turned a blind eye to people drinking outside pubs or swigging from beer cans as they follow the bands on what is the biggest day in the loyalist marching calendar.

But last night a spokesman for the force made it clear they were not prepared to see drink laws flouted.

He said: "Local commanders will be taking steps to reduce the impact of alcohol by putting in place appropriate measures and by using the legislation available to deal effectively with people who commit offences.

"Where appropriate, police will seize alcohol and prohibit its consumption in public places."

The Orange Order, as well as the Royal Black Institution, the Apprentice Boys of Derry and the Ulster Bands Association all warmly welcomed the crackdown.

A spokesman for the Order told us: "We appeal to all those who come to watch our parades to act responsibly and in particular to obey by-laws in relation to alcohol consumption.

"We recognise that irresponsible drinking is an increasing problem surrounding festivals and major public events.

"But alcohol misuse and associated misbehaviour is discouraging some families from attending and enjoying our parades."

More than 80,000 Orangemen will be on the march on Thursday.

One of largest demonstrations will be at Loughgall - the birthplace of Orangeism - with 160 lodges and 80 bands.