SCOTTISH Labour is facing a mammoth summer deputy leadership contest, the Sunday Herald has learned.

An election process of three-and-a-half months is expected to be approved at the party's ruling Scottish executive committee today.

Last night, Labour MSP Monica Lennon, who had been tipped as the frontrunner, ruled herself out of the race, stating she "had no plans to be a candidate".

The winner of the contest will not be declared until either August 31 or September 1. Nominations formally open on May 14, before closing on the 28th of the month.

The timetable is even longer than the party's lengthy leadership contest last year that saw Richard Leonard defeat Anas Sarwar following a bitter campaign.

Nominations in last year's contest opened on September 11, with the result declared on November 18.

Meanwhile, in the deputy leadership election, a "freeze date" of June 22 has been set, meaning any new members signing up afterwards will not be eligible to vote.

Deputy leadership hustings across Scotland will begin from July 8, and ballot forms for party members will be sent out on July 26.

Voting will close on August 30, with the winner declared sometime in the following two days.

An "organisation sub-committee" drafted the recommended timetable, meaning its approval is likely to be a formality. A senior party source confirmed the proposals.

The deputy leadership contest could spark another fiercely fought contest between senior figures in the party.

The Sunday Herald previously reported that Labour MSPs Lennon, Jenny Marra, Jackie Baillie and MP Lesley Laird were expected to go head to head.

Earlier this year, Labour delayed a decision about holding the contest after the post was vacated by Alex Rowley in December 2017. Laird, the shadow Scottish secretary, has been filling the acting deputy leader role.

The Kirkcaldy and Cowdenbeath MP failed to respond to questions from the Sunday Herald on whether she wanted the job on a permanent basis.

However, Laird would be in strong contention due to her role as acting deputy leader and membership of UK Labour leader Jeremy Corbyn's shadow cabinet.

Laird's chances could also be improved by the absence of Lennon, who is in Leonard's shadow cabinet as secretary for communities, social security and equalities.

Lennon was vocal in her support for Leonard's leadership campaign and has voiced backing for Corbyn.

Baillie, who backed Sarwar in the leadership contest, is another possible candidate. The Dumbarton MSP has previously deputised for Labour leaders at Holyrood's First Minister's Questions and is a highly experienced parliamentarian.

Baillie did not respond to questions yesterday about whether she would stand.

Marra, Holyrood's Public Audit Committee convenor, was also unavailable for comment.

Meanwhile, there was speculation last night that Glasgow Labour MSP Pauline McNeill may stand.

McNeill, who backed Sarwar in last year's leadership contest, declined to comment on the reports.