TUNIS, Jan 26 (Reuters) - Tunisia plans a voluntary lay-off programme for more than 50,000 public sector employees starting this year in a major reform to reduce high government spending, a minister told Reuters on Thursday.

Minister of Public Functions Abid Briki said this key reform will start this year but did not give details on how long the reform would take. Reforms to the public sector workforce are politically sensitive in Tunisia.

At 13.5 percent of GDP, Tunisia's public sector wage bill is proportionately one of the highest in the world. The North African country has been under pressure from multilateral lenders to reduce spending to cut its budget deficit.

(Reporting by Tarek Amara; writing by Patrick Markey) ((pat.markey@thomsonreuters.com; +213-661-692993; Reuters Messaging: pat.markey.thomsonreuters.com@reuters.net))