Image copyright CBI Image caption The CBI said its decision to register as a "No" backer was an "honest mistake"

The Confederation of British Industry's (CBI) registration as a campaigner against Scottish independence has been nullified by the elections watchdog.

The business lobby's registration with the Electoral Commission would have allowed it to spend up to £150,000 in campaigning for a "No" vote.

The CBI said it remained a "politically independent and impartial body".

The commission said the group's activities would be monitored during the referendum period.

The CBI had said its registration as a "No" supporter had been an "honest mistake" which had not been signed by an authorised signatory - an explanation which has been accepted by the elections watchdog.

The move, last month, prompted more than a dozen members to resign or suspended their membership from the organisation.

Following the Electoral Commission's decision, a number said they would review their positions after the independence referendum.

Glasgow University, said, "We have no current plans to rejoin the CBI."

Tourism agency VisitScotland said: "We will not be making any decision on this matter until after a discussion with the CBI has taken place."

STV said: "Having taken the decision to resign our membership of the CBI, we will maintain this position until after the referendum on Scottish independence when we will reconsider our position."

Robert Gordon University, said: "We will review our decision to suspend our membership after the referendum in September."

Aquamarine Power Chief Executive Martin McAdam said the wave energy company would consider re-joining the CBI after the referendum.

Economic development agency Scottish Enterprise, said: "Scottish Enterprise's decision to resign from the CBI was based on our commitment to remain impartial during the current debate. We will maintain our stated position and review post referendum."

Highlands and Islands Enterprise, said: "HIE intends to review its relationship with the CBI after the referendum."

The Law Society of Scotland, said: "We will be carefully considering the CBI's recent statements and the response received from the Electoral Commission."

Edinburgh's Heriot-Watt University, said: "The issue will be considered and a decision taken in due course."

The BBC, which suspended its CBI membership between 30 May and 18 September, said: "Our position remains the same and we'll form a view in due course."

Tony Banks, chairman and founder of Balhousie Care Group, and chairman of the pro-independence Business for Scotland group, said: "The organisation needs to go through a revamp of its governance, become more transparent and have a change in leadership before we'd consider rejoining."

The commission said "the only reason" it had removed the CBI from its register was because the business body had not ensured that the person who signed its application was authorised to do so.

John McCormick, electoral commissioner for Scotland, said: "The law, and our own guidance, state who can sign a permitted participant application form. In this case, the CBI submitted a form to the Electoral Commission that had been signed by the wrong person and their application is void.

"The Electoral Commission will meet shortly with the CBI to make sure they understand the campaigning rules at this referendum. We will monitor their activities over the 'referendum period' as part of the monitoring work we do ahead of any election or referendum."

Scotland's independence referendum Who? Voters in Scotland will go to the polls to vote on their country's future. What? They will be asked the yes/no question: "Should Scotland be an independent country?" When? The vote takes place on Thursday, 18 September, 2014.

Following its removal from the list, the CBI said in a statement: "The CBI is a politically independent and impartial body and will ensure that it complies with Electoral Commission guidance to safeguard its political independence.

"As businesses work hard to secure the economic recovery, the CBI has a job to do on behalf of its members and their employees to help create the right conditions for UK companies to grow and prosper, wherever they operate across the world.

"We will continue to do that without fear or favour."

On 18 September, voters in Scotland will be asked the Yes/No question: "Should Scotland be an independent country?"