DUP leader Sir Jeffrey Donaldson has urged peaceful and positive July 12 celebrations across Northern Ireland.
He made the call hours before bonfires built in loyalist areas will be lit ahead of Orange Order parades on Wednesday.
They are a traditional part of the main date in the Protestant loyal order parading season.
Some of the pyres, mainly made by stacking wooden pallets, have been burned already, though the vast majority will be lit late on Tuesday night.
There was condemnation at the weekend when an Irish flag and a picture of Taoiseach Leo Varadkar was put on a bonfire in Co Tyrone.
Police are treating the incident as a hate crime.
On Tuesday evening, police and community representatives were working together to remove material from a bonfire in Rathcoole, Newtownabbey, on the outskirts of north Belfast.
An effigy, above a poster bearing the name of Sinn Fein Councillor Taylor McGrann, appeared on the pyre.
A police spokesperson said they are treating this as a hate crime and have liaised with community representatives with a view to having the material removed.
As unionists we need to recognise that such incidents are self-inflicted wounds.— Sir Jeffrey Donaldson
Sir Jeffrey said the burning of flags or election posts are “self-inflicted wounds” for unionists.
“For those of us who do cherish the legacy of the Glorious Revolution then the best way to show that to others is through peaceful and positive celebrations,” he said.
“Those don’t include the burning of flags or election posters on a bonfire, but thankfully in the vast majority of cases that does not happen.
“Unfortunately, it will be a minority of cases where offence is caused that will dominate the headlines.
“As unionists we need to recognise that such incidents are self-inflicted wounds.
“From fun-days and bonfires on the 11th through to the annual Sham Fight at Scarva on Thursday, for most people it will be time to spend with family and catching up with friends.
“All of us who enjoy the celebrations can play our part in demonstrating to others everything that is best about this time of the year and why it is so important to us all.”
The Eleventh Night fires are traditionally lit on the eve of the Twelfth Of July – a day when members of Protestant loyal orders parade to commemorate the Battle of Boyne in 1690.
The battle, which unfolded at the Boyne river north of Dublin, saw Protestant King William of Orange defeat Catholic King James II to secure a Protestant line of succession to the British Crown.
Most of the estimated 250 bonfires pass off every year without incident but a number continue to be a source of controversy.
