Scotland's Fire Service has been accused of undermining a union after making a pay proposal directly to firefighters.

The proposal is understood to include a 20% pay rise while at the same time dramatically expanding the role of firefighters.

New responsibilities could include dealing with terror attacks and severe flooding, according to a letter sent by the Scottish Fire and Rescue Service (SFRS) to its employees.

However, the Fire Brigades Union (FBU) said the SFRS has bypassed nationally agreed collective bargaining processes by sending the letter before consultation with the union.

In a statement, the union said: "We are of the firm belief that the communication by SFRS, which was directly sent to our members asking them to 'consider the proposal', is a breach of the Working Together Framework.

"It is wholly unacceptable for SFRS to now ignore our FBU structures by contacting members directly stating that the offer 'represents an extremely attractive proposal' without giving any specific details on that proposal as well as any details on harmonisation of terms and conditions.

"We believe this could constitute a deliberate attempt to undermine our consultation with our members."

The union is now "strongly advising" its members to ignore the offer until the proposals have been fully considered by the FBU executive council.

Kirsty Darwent, chair of the SFRS board, said: "This service has set out very clearly how it needs to transform to meet the significant new and emerging risks that Scotland now faces, such as severe weather-related flooding and terror attack.

"We are offering to pay our firefighters more - but we are asking them to do a lot more, by taking on a completely new role to enhance the safety of the communities they serve.

"This is a proposal. We will now enter into formal negotiations with staff and unions, and believe we can reach the right outcome for our firefighters and the people of Scotland."