We present the constraints on inflationary parameters in a flat \Lambda CDM universe obtained by WMAP three year data release , plus smaller scale CMB and two LSS data sets , 2dF and SDSS ( treated separately ) . We use a Markov Chain Monte Carlo ( MCMC ) technique combined with an analytic description of the inflationary spectra in terms of the horizon flow functions ( HFF ) . By imposing a consistency condition for the tensor-to-scalar ratio , we study the constraints both on single field standard inflation and on inflation with the violation of the null energy condition , which leads to a blue spectrum for gravitational waves . For standard inflation , the constraint on the tensor-to-scalar ratio we obtain from CMB data and 2dF05 is : r _ { 0.01 } < 0.26 at 2 \sigma cl . Without the consistency condition between the tensor-to-scalar ratio and the tensor slope , the constraints on the tensor amplitude is not significantly changed , but the constraints on the HFFs are significantly relaxed . We then show that when the third HFF \epsilon _ { 3 } is allowed to be non-zero and to be of order unity , a large negative ( at 2 \sigma ) value for the running of the scalar spectral index in standard inflation is found in any set of data we consider .