Image caption Mrs O'Neill also accused the DUP of using the issue as a smokescreen

Sinn Fein's Stormont leader has rejected DUP calls for the controversial petition of concern to be scrapped.

Michelle O'Neill also insisted an Irish Language Act would be part of the post-election negotiations.

However, she refused to say if it would be a deal breaker for her party.

Launching Sinn Féin's manifesto in Armagh, she said she was not in the business of setting "red lines" ahead of negotiations.

But she did defend the use of the petition of concern, which DUP leader Arlene Foster has suggested should be scrapped.

What is a petition of concern?

If a petition of concern is presented to the assembly speaker, any motion or amendment will need cross-community support.

In such cases, a vote on proposed legislation will only pass if supported by a weighted majority (60%) of members voting, including at least 40% of each of the nationalist and unionist designations present and voting.

Effectively this means that, provided enough MLAs from a particular community agree, that community can exercise a veto over the assembly's decisions.

A valid petition requires the signatures of 30 MLAs.

"Clearly years of unionist misrule, and even in the last number of weeks the attempt to denigrate rights of individuals, has shown that we need to have mechanisms in place that protect peoples' rights," she said.

'Irish unity referendum'

"The petition of concern needs to be used in the manner it was intended, which is to protect minority rights.

"It is others who have abused that position and have used it to deny people rights. That is not acceptable."

Image caption The manifesto sets out a list of 25 priorities

Mrs O'Neill also accused the DUP of using the issue as a smokescreen.

"I think the DUP want to talk about everything but scandal, corruption and RHI," she said.

The 12-page manifesto entitled Equality Respect Integrity - includes the party's ten-point plan set out in the last assembly election in May to deal with problems in health, education, housing and welfare.

But it also contains a list of 25 priorities which are likely to form the template for Sinn Féin's post-election negotiation.

They include:

Full implementation of the RHI inquiry's recommendations

Securing designated special status for Northern Ireland in Brexit negotiations

A commitment to equality and respect to include an Irish Language Act and marriage equality

An island-wide referendum on Irish unity

Ensuring the two governments honour and implement agreements in full

Image caption Mrs O'Neil also repeated the party's opposition to Mrs Foster returning as first minister before the RHI public inquiry concludes

Asked about the DUP's rejection of an Irish Language Act, Mrs O'Neill said: "Look elsewhere, look at Scotland and Wales, they still have a health service and an education service alongside a language act. So we will not be detracted.

"We know what the DUP is attempting to do, to bring away from the fact this election is about arrogance, disrespect and contempt for the public."

'Public concern'

Asked if the Irish language act would be a deal breaker in the post-election talks, she said: " I wont be drawn on a red line."

Mrs O'Neil also repeated the party's opposition to Mrs Foster returning as first minister before the RHI public inquiry concludes.

"While there is a cloud over Arlene Foster in relation to the Renewable Heat Incentive (RHI) scandal we will not be supporting her position of first minister or deputy first minister in an executive office," Mrs O'Neill said.

"We have to have a full investigation. We have public concern and outrage and demands for answers. The RHI scheme has been all of the DUP's making."