Private donations to Northern Ireland's four main political parties soared to over £700,000 in 2007.

Unlike their counterparts in Britain and the Republic, parties here are permitted to keep the identities of donors secret.

This lack of transparency is due to continue until at least 2010 and has raised accountability concerns about Assembly rule.

Details of DUP, Sinn Fein, UUP and SDLP finances in the election year of 2007 were disclosed yesterday, with the publication of their annual accounts.

They show that the official total for donations received by the four parties came to £744,529. In 2006, the total was £296,115.

The two dominant parties at Stormont, DUP and Sinn Fein, achieved surpluses in the 12 month period, despite Assembly poll battle costs.

Sinn Fein, which continues to enjoy strong backing from the US, was also revealed to be a £1m party — its total income in 2007 amounting to £1,068,535.

That gave it the healthiest annual figures of the main local parties.

The SDLP's coffers were substantially boosted by a surge in donations, but it nevertheless recorded a £130,691 deficit for the year.

That figure was dwarfed by a £405,647 deficit for the Ulster Unionist Party in 2007. It has insisted that its overall finances are healthy. They have been boosted by an increased valuation for its Cunningham House headquarters in east Belfast.

The accounts were published by the Electoral Commission, a UK-wide statutory watchdog for elections and party finances.

Key details from the documents included:

DUP: The party's accounts record that it received £190,144 in donations in 2007, compared to just £12,166 in 2006.

The DUP's overall income for the year came to £374,386. It achieved a surplus of £40,446 and reduced its bank loans and overdrafts from £148,410 to £108,718.

The good fortune was reflected on the electoral front, with the DUP securing the First Minister's post.

Sinn Fein: Donations to "Sinn Fein 6 Counties" almost trebled, rising from £103,377 in 2006 to £298,710 in 2007.

The party's account said this "impressive" increase was "due almost entirely to the magnificent work of Friends of Sinn Fein USA". Parties in the rest of the UK are barred from accepting foreign donations.

Sinn Fein's spending last year increased by £318,085, partly due to the Assembly election.

It nevertheless achieved a surplus of £108,330 for the 12-month period.

The overall £1,068,535 income total was partly due to contributions from the wages of each of its elected representatives. This brought in £490,561 last year.

Grants from Assembly and Westminster-related schemes amassed a further £279,264.

The Sinn Fein accounts, however, complained that it is "still being deprived" of Westminster policy development grants. The party's MPs do not take their seats in the House of Commons.

The Electoral Commission yesterday stated that it had fined Sinn Fein £500 for late submission of its accounts.

Ulster Unionist Party: The UUP's accounts refer to a "difficult year" and financial pressures caused by the Assembly election.

Its deficit for 2007 came to £405,647, with income at £376,369 and expenditure more than double this on £782,016.

However, "total funds" are given as £699,084 in credit. That included the asset value of its Cunningham House headquarters, which had its recorded worth increased by some £800,000 due to a revaluation.

The UUP also gives its total for outside donations in 2007 as £33,153, compared to £95,402 in 2006.

SDLP: The party's £130,691 deficit in the year came about through expenditure of £794,365, compared to income of £663,674.

Its overall balance sheet was £45,154 in credit.

Donations to the SDLP from unnamed sources in Ireland and the UK came to £222,522 last year, compared to £85,170 in 2006.

A further £161,576 was brought in through fundraising dinners, compared to £34,385 the previous year.

Séamus Magee, head of the Electoral Commission's Northern Ireland office, yesterday said:

"The accounts of a party are a key source of information for anyone wishing to find out more about a political party's finances.

"The regulatory framework put in place by the Political Parties, Elections and Referendums Act is designed to ensure the integrity of our democratic system and is quite clear on the time-frame that must be adhered to. That is why we are fining parties who did not meet the deadline for submitting their accounts.

"Easy comparison between different parties' statements of accounts is not currently possible because parties and accounting units use different formats and naming conventions.

“The Commission is consulting on prescribing regulations that will set out how accounts must be presented with more consistency and transparency,” added Mr Magee.