Desley has Advocated for Local Residents since 2007.

Desley is an Auckland Councillor representing the Orakei Ward. Prior to that she was Orakei's Local Board chair, a role she held unopposed for 6 years since the formation of the super city in 2010.

Before Auckland Council, Desley chaired the Hobson Community Board for Auckland City Council under the John Banks mayoralty .

She comes from a long political lineage with her great great uncle Sir Henry Brett being the 5th Mayor of Auckland in 1878 and grandfather Sir James Donald a becoming member of the Harbour Board in 1935, Deputy Chairman in 1938 and then Chairman well into  the 1940's.

Desley has been a Justice of the Peace since 1997.

As chair of the Orakei Local Board, Desley’s portfolios include overall Board strategy, finance, rates and governance, the Unitary Plan, walkways and Community development initiatives.

Locally her achievements include leading the construction of the Orakei Basin walkways, and the Hobson Bay walkways.

Regionally she led the charge for Council to purchase Colin Maiden Park keeping this for open space and recreation having seen this designated for terraced housing and apartments in the draft Unitary Plan.

She also led the Board to develop a multi-million dollar agreement with Oceania Football to develop Ngahue Reserve - providing the Community with 70% of the use of two new artificial fields and one training field at no cost to ratepayers.

She also championed the removal of sports field charges from her ward and other isthmus wards following amalgamation which saw this area as the only area to be charged.

Setting up five new residents' associations in the ward, was also another achievement for Desley. The Orakei Ward now has seven residents associations covering each of the ten suburbs making up the ward. This facilitates feedback and communication with residents and ratepayers within the ward.