The Belfast City Marathon could take place on a Sunday for the first time from 2019.
The proposal is one of several major changes which organisers are seeking feedback on, including a new route map which would see the finishing point shifted from Ormeau Park in south Belfast to Stormont.
Belfast City Council's City Growth and Regeneration Committee is set to discuss the proposed changes which have been put forward by Belfast City Marathon Limited at its meeting tonight.
While the council was involved in the administration of the marathon in the past, the Belfast City Marathon Limited is a free standing organisation that has no legal connection to Belfast City Council, other than funding arrangements.
The committee will hear that the council is set to contribute £26,000 to the 2018 race. The marathon on average attracts 18,000 competitors, making it the biggest mass sporting event in Northern Ireland.
The race is estimated to create over £1m in additional economic activity for the city and over £1.5m for charities connected to the event.
The committee will hear that the Belfast Chamber of Trade and Commerce wants the marathon moved from its traditional Monday May Day date to a Sunday due to disruption to business trading and also due to the level of traffic disruption caused.
Councillors will also consider that charges from the PSNI are double the rate on a bank holiday to a standard working day.
Councillors will also be told many other cities hold their marathons on Sundays, including Berlin, Boston, Chicago, London and Dublin where the marathon saw an increase in competitors from 14,000 to 20,000 when it switched to a Sunday.
In a letter to Belfast City Council, the Chamber of Commerce has written that its executive council voted unanimously for the day the marathon is held to move from Monday to Sunday.
The organisation has outlined four reasons for this.
It said: "While retailers normally enjoy an increase in trade on bank holidays, on marathon day trade in the city centre is only half of that experienced on an average Monday."
The chamber also states that it believes a Sunday marathon would encourage more weekend visitors to participate or support the event, that most international marathons are held on Sundays and that a Sunday event would benefit businesses in the city centre, who cannot open until 1pm.
The letter adds: "Both Belfast Marathon Company and Belfast Chamber of Trade and Commerce are committed to bringing more people into Belfast.
"To that end, we would be keen to explore opportunities to work together to promote our respective and shared goals. The chamber would be grateful if the Belfast Marathon could be moved to Sunday with effect from 2019."
Belfast City Marathon has been running for 36 years and in that time the route has only changed once - in 2005 to create a flatter course. However, the race reverted back to its traditional route in 2006.
Now marathon organisers are trying again to make a major change to the route.
The proposed new route retains City Hall as the starting point, but instead of immediately heading east, it would pass through the city centre towards Queen's University, along the River Lagan and around the edges of Ormeau Park.
It would then travel along the Albertbridge Road and out towards the Sydenham bypass.
Reverting back to the current route, the new one would cross the Queens Bridge and moves through the city centre towards the Falls Road, crossing the peaceline to the Shankill Road.
There the proposed new route would change, moving up towards Ardoyne and past the Waterworks before heading east again through Titanic Quarter and Victoria Park and finishing in the leafy suburbs of Stormont.