Counting gets under way on Monday in the Seanad election when an electorate of 1,150 gets to select 43 of the 60 senators in the Upper House.

The 158 TDs, 941 councillors, and 53 of the 60 outgoing Senators (seven were elected to the Dáil), has a vote on each of the vocational panels - Administrative, Agricultural, Cultural and Educational, Industrial, and Labour.

With quotas of between 70 and 140 votes, Fianna Fáil and Sinn Féin are expected to be the big winners because of their success in the 2014 local elections, which increased their electorate.

Fianna Fáil are expected to get around 17 seats, up from 13 and Sinn Féin are likely to return seven or eight, up from three, expected to include Pádraig Mac Lochlainn who lost his Donegal Dáil seat in a shock defeat.

Fine Gael are thought likely to return around 12 while Labour will have at most three seats in the Seanad. Independents will vote in about four of their number.

Thirteen former TDs who lost their Dáil seats are running for the Seanad.

And if any of the electorate graduated from NUI or Trinity they get another vote for the three senators on each if the above panels.

Counting for the university panels gets under way on Tuesday after 11 am, the deadline set for arrival of post in the postal ballot.

While a virtually 100 per cent turnout is expected for the vocational panels, only around 30 per cent at most is expected in the university panels.

Postal voting caused controversy because of the numbers of voting papers returned by An Post as undelivered to Trinity and the NUI.

This was either because nobody was home for the registered post delivery and did not collect the papers within three days at the local sorting office, or the ballot was sent to and old address.

Postage accounts for €2.4 million of the approximately €2.7 million total cost of the Seanad elections.

The taoiseach in a new government will appoint 11 nominees to the Seanad.