Studies on French adults using a written lexical decision task with masked priming, in which targets were more primed by consonant-(jalu-JOLI) than vowel-related (vobi-JOLI) primes, support the proposal that consonants have more weight than vowels in lexical processing. This study examines the phonological and/or lexical nature of this consonant bias (C-bias), using a sandwich priming task in which a brief presentation of the target (pre-prime) precedes the prime-target sequence, a manipulation blocking lexical neighbourhood effects. Results from three experiments (varying pre-prime/prime durations) show consistent C-priming and no significant V-priming at earlier and later processing stages (50 or 66 ms primes). Yet, a joint analysis reveals a small V-priming, while confirming a significant consonant advantage. This demonstrates the contribution of the phonological level to the C-bias. Second, differences in performance comparing the classic versus sandwich priming task also establish a contribution of lexical neighbourhood inhibition effects to the C-bias.