Sinn Fein has again been accused of politicising education after claims it breached Department of Education rules on canvassing in the run-up to last week's Mid Ulster by-election.
Publicly-funded schools were warned that their premises were not to be used if it could be "regarded as aimed at canvassing for votes for any particular political party or any particular political party election candidate".
But just days before voters went to the polls, Sinn Fein candidate Francie Molloy was filmed inside a school with Education Minister John O'Dowd – whose department issued the ban.
DUP education spokesman Mervyn Storey said this was a case of "Sinn Fein saying do as I say but not as I do".
"There seems to be a certain level of hypocrisy involved here. Sinn Fein needs to clarify the position," he said.
"What's the point of one Sinn Fein MLA issuing very rigid guidelines when another Sinn Fein MLA rides a coach and horses through them? Of course, double standards would be nothing new for some in Sinn Fein."
A circular entitled "the use of school premises for political events" was issued to all grant-maintained schools – including controlled and Catholic maintained – by the Sinn Fein controlled department.
It stated: "School authorities will be expected to adhere to this advice, especially in the run-up to the forthcoming by-election in the Mid Ulster constituency.
"A school shall not be used for political meetings, the transaction of any political business or for any purpose connected directly or indirectly with Parliamentary, Assembly or Local Government elections, except as polling booths.
"This is the current legal position which prohibits the holding of political meetings in a grant-aided school, including meetings which could be regarded as aimed at canvassing for votes for any particular political party or any particular political party election candidate."
But the advice appeared not to extend to Sinn Fein, after the party's winner in Thursday's by-election, Francie Molloy, was photographed in Catholic maintained schools just days before constituents cast their vote.
On Monday, February 11, Mr Molloy, who is also the local Sinn Fein MLA, was videoed on An Phoblacht News/Sinn Fein TV, directly outside the gates of Holy Trinity College in Cookstown, a Catholic maintained school, being endorsed by one of its teachers, Peter Canavan.
Mr Canavan, who is also a former Tyrone GAA star and now manager of Fermanagh, backed Mr Molloy in the by-election video.
In the footage he describes Mr Molloy as "a very ardent supporter of Holy Trinity College and our pursuit of a new build".
Just 10 days later Mr Molloy was back in Holy Trinity, which sits in the Mid Ulster UK Parliament constituency, on a visit with Sinn Fein Sports Minister Caral Ni Chuilin.
Then, on February 25, he was snapped with Education Minister John O'Dowd at Joseph's Primary School in Galbally – the same Co Tyrone village where Mr Molloy launched his Mid Ulster by-election campaign just three weeks earlier on February 3.
It is not the first time Sinn Fein has been accused of politicising education.
The Education Minister was criticised last year after it emerged that three Sinn Fein members – a party opposed to academic selection – had been placed on to the board of governors of grammar schools in Londonderry including Paul Kavanagh, a special adviser to Deputy First Minister Martin McGuinness and a convicted IRA bomber.
There was uproar after it emerged Mr O'Dowd had rubberstamped the appointments of Mr Kavanagh and Mary Nelis –against the wishes of the school – as governors at Lumen Christi College in Derry.