Northern Ireland First Minister Michelle O’Neill is to attend a Police Service of Northern Ireland graduation ceremony tomorrow, a Sinn Féin spokesperson has confirmed.
It will be the first time that a party member will attend such an event in the force’s history.
The development comes after Ms O'Neill pledged to represent "our whole community" as she became the first nationalist first minister last weekend.
Ms O’Neill will be accompanied by Policing Board member and Sinn Féin MLA Gerry Kelly.
"Tomorrow the PSNI student officer attestation takes place where a number of new recruits will graduate," a Sinn Féin spokesperson said.
"Michelle O’Neill will be in attendance and will join the ceremony. Sinn Féin Policing Board member Gerry Kelly MLA will also attend."
Efforts have been made to boost Catholic representation in the PSNI as about a quarter of the force's members are from a Catholic background.
After a major PSNI data breach last August, a representative group said the recruitment of candidates from the Catholic, nationalist and republican community had been "severely dented".
Democratic Unionist Party MP Gregory Campbell, the party’s justice and security spokesperson, said that Sinn Féin attending the PSNI graduation was "much better than not going".
"Twenty-three years later, it is better late than never," he told BBC Radio Ulster.
"I think I recall around four years ago when there was a similar type of event when Arlene Foster was first minister, and Sinn Féin were extremely reluctant to go then, but if they’re over the line now that’s good."
He said he would now like to see the party support the recruitment of Catholics, as well as Protestants, to the PSNI.
He added: "It’s an unequivocal welcome for a step that should have occurred many years ago, and hopefully it can lead on to further support for getting people across the community to join the police."
DUP MLA and the party’s Policing Board group leader Trevor Clarke said the decision was overdue but welcome.
"The PSNI was formed in November 2001 therefore whilst late and long overdue, it is good that Sinn Féin has lifted its boycott of PSNI passing out ceremonies.
"The PSNI has struggled to recruit people from a Roman Catholic background and at least one previous chief constable cited a lack of political leadership within the nationalist community.
"Undoubtedly Sinn Féin’s lack of support of PSNI recruits was a contributing factor," Mr Clarke added.
