A union boss has called on college management to "stop spinning and resume talking" after thousands of lecturers staged a strike in a long-running dispute over pay and conditions.

The Educational Institute of Scotland (EIS) said members walked out on Thursday in the first of an escalating programme of strikes over the refusal of college management to honour a deal that was reached more than a year ago.

The agreement promised equal pay for lecturers in all colleges and national terms and conditions following years of pay inequity for lecturers doing the same jobs in different colleges, the EIS said.

The union said Colleges Scotland declined meetings offered on Thursday and Friday, a claim which the organisation denied.

EIS general secretary Larry Flanagan said: "Despite Colleges Scotland repeating loudly in the press that they are 'always willing to talk', it is clear that they currently have absolutely no interest in engaging in discussions with EIS negotiators to resolve this dispute.

"The EIS offered to meet Colleges Scotland on Thursday. They declined.

"The EIS offered to meet Colleges Scotland today. They declined while also seeking to impose pre-conditions on any future talks.

"These are not the actions of an organisation that is keen to resolve a dispute.

"Their claims that they are 'always willing to talk' have been exposed as just another piece of costly spin from an increasingly desperate management side.

"It is time for Colleges Scotland to stop spinning and resume talking."

A Colleges Scotland Employers' Association spokeswoman said: "We all want to see an end to the unnecessary strikes about proposed changes to terms and conditions.

"Both sides were tasked with scheduling a further meeting and this task is currently in progress.

"Contrary to the EIS's statements, no meeting requests have been declined. At this stage, we have offered to meet on Tuesday to continue discussions.

"Pay and conditions are inextricably linked and are an intrinsic part of the agreement of March 2016 that the EIS signed up to.

"We look forward to a change of tack from the EIS and real engagement on harmonisation of pay and conditions in the next round of talks."

More than 4,600 members were eligible to take part in Thursday's strike, which affected about 20 institutions and followed a 96% vote in favour of the action in a recent ballot of Further Education Lecturers' Association (EIS-FELA) members.

A second strike is planned for next Wednesday, with the strike then escalating to two days per week and then three days per week unless the deal is honoured.

A revised offer from Colleges Scotland was accepted last year, with staff promised wage rises as well as work between colleges and the union to develop a more ''harmonised'' pay deal across the workforce.