Opposition leader John Brogden rewarded the Southern Highlands MP with the shadow ministries of infrastructure and planning, the Illawarra and reform of government.

Ms Seaton said the portfolios were a great challenge.

"The main thing I will be bringing to these roles is the experience I gained through my role as member of the Southern Highlands," she said.

"I am really looking forward to tackling these challenges."

Ms Seaton said the Government's whole approach to infrastructure was in crisis.

"The latest fiasco with the Menangle Bridge is a prime example where they just ignored the need for infrastructure and tried to cover it up.

"More broadly I will be tackling the failure of the Carr Government to plan properly for services.

"Quite simply, the Carr Government is too lazy to properly think through better planning processes that reflect the neighbourhood character.

"Through this lack of planning, it has failed to meet the needs of local people and this is something I will be working towards.

"Places like Wollondilly and the outer parts of south-western Sydney are at present being threatened with the lack of infrastructure and unplanned urban sprawl."

"In all three portfolios I will set out to make the Government accountable for every decision they do or do not make."