Sinn Fein's Michelle O'Neill has told DUP leader Arlene Foster to "stop fixating on Gerry Adams".
Mrs O'Neill, who recently replaced Martin McGuinness as leader of Sinn Fein in Northern Ireland, said Mrs Foster needs to recognise that she is in charge of her party in the region, not party president Gerry Adams.
Speaking following a 5 Leaders; 5 Days event organised by the Northern Ireland Chamber of Commerce, Mrs O'Neill said: "I'm the leader of Sinn Fein in the North, whether Arlene wishes to recognise it or not.
"I think Arlene is fixated on Gerry Adams and I think she is fixated on the politics of fear. I think that's a really unfortunate way you need to motivate your electorate."
Mrs O'Neill was referring to Mrs Foster's frequent references to Gerry Adams during pre-election events.
Launching the DUP's manifesto on Monday, Mrs Foster mentioned the Sinn Fein president 12 times.
She claimed that a victory for Sinn Fein would give the party and Gerry Adams a "hugely significant world-wide propaganda boost".
Mrs Foster also said electoral polls had shown that the Democratic Unionist Party and Sinn Fein would be "neck-and-neck" in the March Stormont election.
However, Mrs O'Neill said: "It is over to the electorate to have their say. I wouldn't presume what the electorate will do. I wouldn't be that arrogant."
She insisted that should Sinn Fein and the DUP be returned as the two biggest parties after the election, their vast differences on major issues such as legacy, a border poll and an Irish language act were "not insurmountable".
"I want the institutions to work. Sinn Fein are committed to making the institutions work. We don't need a new agreement. But we can only be in government with partners who are wedded to respect, equality and integrity," she said.
Earlier Mrs O'Neill told members of the business community during the Northern Ireland chamber event in Magherafelt that the "biggest threat to jobs and our economy in the current climate is Brexit".
She said that the best way forward is to secure designated special status for Northern Ireland to remain within the EU.
"We are currently on a diplomatic offensive across Europe where we are finding a lot of sympathy for the North to remain. But we need wider civic society, the business sector, trade unions and everyone who opposes Brexit to work together on that offensive."