  In the framework of the multiconfiguration Dirac-Hartree-Fock method, we
investigate the transition properties of four excited states in the $2p^53s$
configuration of neutral neon. The electron correlation effects are taken into
account systematically by using the active space approach. The effect of
higher-order correlation on fine structures is shown. We also study the
influence of the Breit interaction and find that it reduces the oscillator
strength of the $^3P^o_1 - ^1S_0$ transition by 17%. It turns out that the
inclusion of the Breit interaction is essential even for such a light atomic
system. Our ab initio calculated line strengths, oscillator strengths and
transition rates are compared with other theoretical values and experimental
measurements. Good agreement is found except for the $^3P^o_2 - ^1S_0$ M2
transition for which discrepancies of around 15% between theories and
experiments remain. In addition, the impact of hyperfine interactions on the
lifetimes of the $^3P^o_0$ and $^3P^o_2$ metastable states is investigated for
the $^{21}$Ne isotope (I=3/2). We find that hyperfine interactions reduce the
lifetimes drastically. For the $^3P^o_0$ state the lifetime is decreased by a
factor of 630.
