Former Conservative MP Ed Holder officially declares candidacy for London mayor

After days ofmedia reports citing unnamed 'sources,' former London West Conservative MP Ed Holder has made it official: he intends to run to be the city's next mayor.

The official announcement is set to take placeThursday at Innovation Works building in downtown London.

Holder held a federal cabinet post as minister of state forscience and technology under the Conservative government of former Prime Minister Stephen Harper.

He ran and lost to former television news anchor Kate Young in London West in the 2015 federal election.

Holder sought the Ontario Progressive Conservative nomination for London West, but withdrew in Januaryfollowing the dismissal of then-party leader Patrick Brown.

The former MP joins an increasingly crowded field of candidates vying for the top job at city hall after mayor Matt Brown announced he would not be seeking a second term.

There are now 14 candidates who have filed papers.

The race could be an interesting one, as it would be the first in the country to use ranked ballots.