UCU has written to the 61 universities* to inform them of an escalating wave of strikes over a four-week period that will begin with a five-day walkout either side of a weekend. There will then be four days of strikes from Monday 5 - Thursday 8 March and a full five-day walkout the following week (12 - 16 March). The strike dates are:

Week one - Thursday 22 and Friday 23 February (two days)

Week two - Monday 26, Tuesday 27 and Wednesday 28 February (three days)

Week three - Monday 5, Tuesday 6, Wednesday 7 and Thursday 8 March (four days)

Week four - Monday 12, Tuesday 13, Wednesday 14, Thursday 15 and Friday 16 March (five days)

Due to their academic calendar four universities - King's, Queen Mary, Edinburgh and Stirling - will not take action in week one. They will start their action in week two on Monday 26 February. They will then walk out for two days on Monday 19 and Tuesday 20 March.

Last week talks between UCU and the employers' representative Universities UK (UUK) ended without agreement and UUK's plans to transform the scheme were forced through by the chair's casting vote.

The dispute centres on UUK's proposals to end the defined benefit element of the Universities Superannuation Scheme (USS) pension scheme. UCU says this would leave a typical lecturer almost £10,000 a year worse off in retirement than under the current set-up.

In the recent strike ballot UCU members overwhelmingly backed industrial action. Overall, 88% of members who voted backed strike action and 93% backed action short of a strike. The turnout was 58%. A full breakdown of the results by institution is available here.

UCU general secretary Sally Hunt said: 'Staff who have delivered the international excellence universities boast of are understandably angry at efforts to slash their pensions. They feel let down by vice-chancellors who seem to care more about defending their own pay and perks than the rights of their staff.

'Strike action on this scale has not been seen before on UK campuses, but universities need to know the full scale of the disruption they will be hit with if they refuse to sort this mess out.'

Seven universities^ failed to meet the government's new 50% turnout requirement for action to be allowed. Those institutions are being balloted again for strike action and their ballots will close on Friday 16 February.

All seven voted for action in the previous ballot. If they do so again, and at least 50% participate in the vote, they would be able to join the action from Monday 5 March.

* Universities affected by strike action

Aberdeen, University of Aberystwyth University Aston University Bangor University Bath, University of Birkbeck College, University of London Bristol, University of Brunel University Cambridge, University of Cardiff University City, University of London Courtauld Institute of Art Cranfield University Dundee, University of Durham University East Anglia, University of Edinburgh, University of Essex, University of Exeter, University of Glasgow, University of Goldsmiths, University of London Heriot-Watt University Hull, University of Imperial College London Institute of Education Keele University Kent, University of King's College London Lancaster, University of Leeds, University of Leicester, University of Liverpool School of Tropical Medicine Liverpool, University of London School of Hygiene and Tropical Medicine Loughborough University Manchester, University of Newcastle University Nottingham, University of Open University Oxford, University of Queen Mary, University of London Queen's University Belfast Reading, University of Royal Holloway, University of London Royal Veterinary College, University of London Salford, University of Senate House, University of London Sheffield, University of SOAS, University of London Southampton, University of St Andrews, University of Stirling, University of Strathclyde, University of Surrey, University of Sussex, University of University College London Scottish Association for Marine Science at University of the Highlands and Islands Ulster University University of Wales University of Warwick University of York

^ Universities being balloted again for action

Birmingham, University of

Bradford, University of

London School of Economics

Ruskin College

St George's, University of London

Suffolk, University

Swansea University