A vote for Scottish independence would drive a wedge between people in Northern Ireland, a DUP MP claimed.
A yes vote on September 18 would ensure further division and encourage republicanism, Ian Paisley Jnr said.
The Scottish government has said if the country becomes independent its future relationship with the rest of the UK will be as "rich and close" as that between the UK and the Republic of Ireland.
Mr Paisley, North Antrim MP, told the House of Commons: "The unnerving and unsettling effect that a division in this wonderful union would have is that it would get the tails up of Irish republicans in my part of the kingdom, and would drive another wedge into the hearts and souls of people in Ulster."
Martin McGuinness has also said the debate over Scottish independence could create divisions in Northern Ireland.
Others including Tony Blair's former chief of staff Jonathan Powell have raised concern about the effects of a rupture on Northern Ireland in potentially reopening the constitutional question.
Sinn Fein has pressed for a border poll on Irish unity in the lifetime of the next Stormont Assembly.
Historically Northern Ireland shares strong cultural links with Scotland, but there has been no mention of a political bond between the two should the larger nation break away.
A White Paper published by the Scottish government said independence will "recognise the distinct political identities of Scotland and the rest of the UK and allow us to work together in a more democratic environment with a renewed partnership as close allies and friends".
It planned a "substantial" diplomatic presence in London and Dublin and pledged to be active participants in the British-Irish Council.
The devolution of corporation tax from London to Belfast is a demand from Stormont politicians who want to cut it in line with the rate imposed by the Republic of Ireland to encourage investment.
Scottish First Minister Alex Salmond has said cutting the rate in an independent Scotland could lead to a jobs boom.