JUST over half of TUV voters plan to give the DUP their second preference in Thursday's assembly poll, according to the latest survey.

Polling on behalf of the Institute of Irish Studies-University of Liverpool/The Irish News suggests Sir Jeffrey Donaldson's calls for voters to transfer to other unionist parties is having mixed results, with only 54 per cent of those voting for Jim Allister's party saying they'll give the DUP a second preference.

In a single transferable vote (STV) election, only a minority of candidates tend to exceed the quota on the first count, meaning they subsequently rely on transfers both from fellow party candidates and elsewhere if ultimately they are to secure a place in the assembly.

Read More: Institute of Irish Studies-University of Liverpool/The Irish News poll results

The survey found nearly two-thirds of DUP voters (62.8 per cent) will give a second preference to the Ulster Unionists, while a quarter (24.3 per cent) will opt for the TUV.

However, the survey indicates that UUP voters won't necessarily reciprocate, with only around one-third transferring to the DUP (32.6 per cent) and 27.1 per cent giving the TUV their second preference.

Alliance, the SDLP and Ulster Unionists appear best placed to pick up second preferences, with just over half of Sinn Féin voters (52.2 per cent) transferring to Colum Eastwood's party. However, just one quarter of SDLP voters (24.3) will transfer immediately to Sinn Féin, with the highest proportion (37.8 per cent) giving their second preference to Alliance. The SDLP is forecast to pick up initial transfers from 33.1 per cent of Alliance voters, while Sinn Féin and the Ulster Unionists will both get a second preference from 15.1 per cent of those who support Naomi Long's party.

Just less than one-in-10 SDLP voters (9.3 per cent) will transfer immediately to the Ulster Unionists, while 5.4 per cent of the latter's supporters will reciprocate.

Some 17.4 per cent of Sinn Féin voters said they would transfer to Alliance in the first instance, with 9.4 per cent preferring to give the Greens a second preference. Both Aontú and People Before Profit would pick up a second preference from 7.1 per cent of Sinn Féin voters.

Slugger O'Toole deputy editor David McCann said the destination of votes cast down the ballot would be crucial in some instances.

"In an STV election transfers can be absolutely critical in shaping the outcome of the final seats," he said.

"Numerous times we have seen how people's preferences can turn what were thought as solid seats into real contests."

He said the Institute of Irish Studies-University of Liverpool/The Irish News illustrated how how critical transfers will be in the latter stages of counting, particularly within unionism.

"In more than five constituencies transfers from the TUV and UUP could be critical in helping the DUP across the line," he said.

"They need these to flow in big enough numbers to make a difference."