A theoretical method for determining the effects of static applied electric fields F on the dielectronic recombination (DR) cross section sigma is described. Distorted-wave theory and the isolated resonance approximation are invoked, in an angular momentum average formalism. First, the intermediate-state Hamiltonian is diagonalised in a basis of high Rydberg state functions of fixed principal n and orbital magnetic m quantum numbers. Fine structure is included, and provision is made for the effects of field ionisation. Then, the explicitly F-dependent DR cross section, integrated over continuum electron energy ec, is obtained as Sigma n,m integral dec sigma nm (ec) identical to Sigma n,m Omega nm identical to Omega tot. Results are displayed for ground-state sodium sequence ions of net charge Z1<or=6, undergoing intrashell ( Delta ns=0) dipole excitations.