SPENDING by Sinn Féin's northern arm was double its nearest political rival last year at £1.14m.
The party's outlay in the 12 months to December 31 2017 exceeded its income by £130,000, latest figures from the Electoral Commission reveal.
The electoral watchdog yesterday published the financial accounts for Northern Ireland parties with an income or expenditure of more than £250,000.
Sinn Féin's accounts show that £437,000 of its income came from donations and £78,000 from fundraising.
With an expenditure of £552,000, the Ulster Unionist Party was the region's second highest spender, exceeding its income across the year by £94,000.
Its accounts describe the financial consequences of losing two MPs in last year's general election as "profound". The party subsequently laid off staff, the accounts state.
The DUP spent £461,000 from an income over the 12-month period of £510,000.
Arlene Foster's party received £152,500 in donations and netted £123,000 from its annual conference.
Alliance's outgoings over the same period were £355,000 from an income of £360,000.
Naomi Long's party received £66,000 in donations last year and banked £39,000 from its annual conference.
In total, the four parties spent just over £2.5m, a significant reduction on the £3.3m spent in 2016.
Earlier this month the Electoral Commission published the financial accounts of Northern Ireland parties with an expenditure of less than a quarter of a million pounds.
The figures showed the highest spender in this bracket to be the SDLP, which had an outlay of £220,000 from an income in 2017 of £237,000.