In Parliament David was a member of key select committees - Public Administration, Public Accounts and Home Affairs. He was also a Shadow Justice Minister between 2007 to 2010 and then was a member of the Coalition Government from 2010 as Parliamentary Private Secretary to the Cabinet Office Ministers Francis Maude and Oliver Letwin, and Environment Secretary Owen Paterson from 2012 to 2014 until he resigned to lead a law change to toughen up knife crime sentencing.
David championed many issues in Parliament - criminal justice, drugs and alcohol treatment, family policy, religious liberty, international human rights, welfare reform, refugees, and immigration detention. David took a particular foreign policy interest in the countries of Israel, Burma, Turkey and Cyprus.
David led changes in national policy and legislation - making the extradition law with USA fairer having stopped the extradition of his constituent Gary McKinnon, establishing the compensation fund for victims from prisoners’ earnings, ensuring mandatory prison sentences for knife offenders (known as ‘Enfield’s Law’ after a spate of local knife fatalities), stopping the relaxation of Sunday Trading laws, increasing provision for child refugees, securing additional funds for Universal Credit and disability benefit recipients, and was architect of the new curriculum requirement of Relationships Education and Relationships and Sex Education.