The DUP has said it is deeply concerned that a former soldier is facing prosecution for a controversial killing while many families of those murdered by paramilitaries are still awaiting justice.
The Ulster Unionists called for justice to be "applied equally and fairly to all" following the decision to charge the ex-soldier over the killing of a Catholic man at an Army checkpoint.
After re-examining the case, the Public Prosecution Service (PPS) yesterday announced its intention to prosecute a 48-year-old former Grenadier Guardsman for gross negligence manslaughter.
Aidan McAnespie was shot in the back as he walked through a border security checkpoint in Aughnacloy, Co Tyrone, in February 1988. The 23-year-old was on his way to the local GAA pitch.
His family claimed he had been deliberately targeted after a sustained campaign of harassment by soldiers.
The decision to prosecute David Jonathan Holden follows a 30-year-campaign for justice by the McAnespies.
Mr Holden insisted the shooting was an accident, claiming his hands were wet and his finger slipped on the trigger of his heavy machine gun.
He was charged with manslaughter in 1988 but the case was later dropped.
The PPS reviewed that decision after the case was referred to it by Attorney General John Larkin.
DUP MP Sir Jeffrey Donaldson said: "We are very disappointed that yet again it is a member of the armed forces facing prosecution when there are thousands of families across Northern Ireland whose loved ones were murdered by terrorists for whom the wait for justice has been far too long.
"This decision to prosecute a soldier gives lie to the claim by some that what we have is an even-handed process.
"I see no evidence that the police and the PPS are currently active in pursuing the prosecution of those responsible for 90% of deaths in the Troubles."
Ulster Unionist MLA Doug Beattie said he had no issue with the PPS deciding to prosecute former soldiers "if that's where the evidence leads".
But he stressed that exactly the same process must apply equally to everyone "including those who were involved in terrorism".
"Evidence must be followed in all legacy cases - whether they involve soldiers, police, civilians, terrorists or politicians. This has been my clear stance from the very beginning but I am now becoming genuinely concerned that this seems only to apply to a small number of individuals and selective cases," he said.
TUV leader Jim Allister said: "People are entitled to ask, given that the vast majority of killings during the Troubles were the result of terrorist murder, why we are seeing a seemingly endless procession of soldiers coming before the courts, while terrorists enjoy freedom. The imbalance is clear and nauseating."
The Attorney General had asked the PPS to re-examine the circumstances of the case following a request by the family for a fresh inquest. He made the referral after reviewing the findings of a report into the shooting by the Historical Enquiries Team.
It is understood the decision to prosecute hinged on the findings of a fresh ballistics report commissioned by the PPS.
A PPS spokeswoman said: "Following careful consideration of all the evidence currently available in the case, and having received advice from senior counsel, it has been decided to prosecute a former soldier for the offence of gross negligence manslaughter.
"The evidence includes further expert evidence in relation to the circumstances in which the general purpose machine gun was discharged, thereby resulting in the ricochet shot which killed Mr McAnespie."
It is understood Mr Holden was informed of the prosecution decision by email yesterday.
Formal papers will be served on his legal representatives in the coming weeks.
The Irish Government conducted its own inquiry into the shooting which was headed by the then Deputy Garda Commissioner Eugene Crowley.
While a government-approved summary of the report was given to the McAnespies in 2002, Dublin has declined to pass the entire document to them.
Irish Justice Minister Charlie Flanagan has claimed that disclosing the entire content of the Crowley Report would be a breach of trust with people who gave information.
Paying tribute to the McAnespies for their 30-year campaign for justice, Sinn Fein MLA Linda Dillon said: "I am calling once again on the Irish Government to release the Crowley Report immediately so that as much information to assist with full disclosure for the case is made available.
"Hopefully this will begin the process of closure for the family."