Fundamental to democratic politics is the quality of representation of constituents' interests by elected officials. This article statistically examines a case of substantive policy advocacy in Great Britain: the issues of wait times and health rationing by the National Health Service (NHS), salient throughout the Blair years. An increase in constituent need for care implies an increase in demand for parliamentary representation, yet representation will not necessarily be supplied, because legislators juggle conflicting interests. We measure representative action using parliamentary questions from 1997–2005. Party and parliamentary status and a set of indicators of the health of British citizens provide measures of political supply and constituent demand. Employing count-regression techniques, we find increased parliamentary questions as the proportion of individuals with some high health risks rises, but opposite results for other health risks. Evidence of political supply is much more consistent, suggesting that political careerism goes a long way towards explaining whether MPs table any questions at all in this policy area.