If you think that the heterogeneous, polyvalent world is a separate structure in its own right, the law is disruptable. The Carnival can be held on the church steps. But if this is not the case, if the carnival and the church do not exist independently of each other, the pre-Oedipal and the Oedipal are not separate discrete states - if, instead, the Oedipal with the castration complex is what defines the pre-Oedipal, then the only way you can challenge the church is from within an alternative symbolic universe. You cannot choose the imaginary, the semiotic, the carnival as an alternative to the law. It is set up by the lae precisely in its own ludic space, its area of imaginary alternative, but not as a symbolic alternative. So that, politically speaking, it is only the symbolic, a new symbolism, a new law, that can challenge the dominant law.
No, it is not Zizek (the tone should give that away), but Juliet Mitchell writing in 1984 in Woman, the Longest Revolution. Considering theory problematises teleology at almost every point it is something of an embarrassment when I realise my own teleological proclivities, in this case concerning our supposed 'advance' in the reading of Lacan.