A Glasgow Labour councillor's £12,000 council tax debt goes back almost 20 years, the Sunday Herald can reveal.

Cecilia O’Lone’s arrears started in the first year of devolution, 1999, and include a surcharge following a council application for a summary warrant.

In Glasgow, it was reported that eight councillors owed almost £52,000 between them, but the largest debt was incurred by Calton councillor O’Lone, who was first elected last year.

In 2016, it was reported that Glasgow City Council was owed £138 million in unpaid council tax.

Individuals can, through reasons such as redundancy or bereavement, miss payments, but a local authority source said there was a “big difference” between arrears of two months and two decades.

A breakdown of O’Lone’s £12,020 council tax debt reveals arrears for 13 successive years. In 1999, the figure was £310, after which there were arrears of £748, £956, £1051, £261 and £800 in the five years after the original debt was incurred.

In 2005/06, another £1,144 was added to the total, after which the debt grew year-on-year by £1,149, £1,157, £1,167, £1,178 and £915.

According to the council, £1,122 of the £12,020 was a 10 per cent “statutory addition”. This penalty is added if the “chargepayer” fails to make payment and the sheriff court is petitioned for a summary warrant. It is understood O’Lone has a payment plan in place.

Under local government legislation, elected members cannot vote on certain budget matters if they are two or more months in arrears.

Councillors in this position who attend formal meetings about council tax have to declare their arrears, and a failure to do so is an offence.

A Scottish Labour spokesperson declined to say whether O’Lone informed the party about the debt when she applied to be a candidate.

Scottish Conservative Glasgow councillor Tony Curtis said: “Voters will be appalled at this state of affairs.”

Councillors have a key decision-making role on services such as education, social work and culture, as well as being able to vote on budgetary matters.

However, an investigation last year revealed that more than 30 councillors in Scotland were in arrears on their council tax, a key charge that funds services.

The collective debt stood at more than £140,000 and some councillors, like O'Lone, owed their local authorities several thousand pounds.

A Labour insider said the O'Lone revelations raised questions, particularly on the disclosure requirements expected of prospective council candidates.

In the "new candidate application pack", individuals had to sign a declaration which stated: "I will declare to the interviewing panel any matters in my political or personal record which, if revealed, could publicly embarrass the Labour Party or affect public confidence in my position as a representative."

O’Lone’s register of interest states that she works 16 hours a week at the Gladiator Programme [a children's health project] which is on top of her £16,927 council salary. She has benefited from £977 in travel that was “paid by council”.

A spokesman for the council said: "Council Tax supports a wide range of frontline services. It is important that everyone that can pay does pay."

O’Lone did not return the Sunday Herald’s call.