The political reform group Democracy Matters has published wide-ranging proposals for Seanad reform, which it says will not require a referendum.

In a document drawing on its own views and those of the main political parties, the group identifies a series of principles that it claims enjoy broad political support.

These include votes for citizens in Northern Ireland and abroad, and a role for the Seanad in EU legislation and scrutiny.

Democracy Matters is made up of Senators who led the campaign to reform the institution in last year's referendum, as well as former tánaiste Michael McDowell.

Senator Katherine Zappone insisted its proposals would not require another referendum.

Mr McDowell said the current Seanad was a "rotten borough" populated by professional politicians and their cronies.

Barrister and commentator Noel Whelan said the campaign would aim to irritate, provoke and shame the political world into taking action on Seanad reform.

The group said it would be seeking support from across the political spectrum and would be looking with particular interest at the Labour backbenches.

Mr McDowell said it would also welcome support from the Reform Alliance.

But he insisted he had had no contact with the group about its activities and would not be attending its conference in the RDS on Saturday week.