In 1835 the English Lord Chancellor Lyndhurst introduced into the House of Lords a bill to correct an ambiguity in the law concerning marriages within prohibited degrees. The existing law, based on the 1533 Henrican statute fixing the degrees of consanguinity and affinity, specified that marriages within prohibited degrees could be annulled at any time within the lifetime of both spouses by the Ecclesiastical Court. Lord Lyndhurst argued that the uncertain status of such “voidable marriages” created an inconvenience and hardship for the married persons and especially for their children, who could during their parents' lifetime be declared illegitimate. His specific motive was to guarantee the legitimacy and inheritance of the son of the seventh Duke of Beaufort, who had married his deceased wife's half-sister, a relationship within the prohibited degrees. Lyndhurst proposed that parliament pass a bill to limit to two years the time within which marriages could be annulled.
The consensus in parliament was that the ambiguity of “voidable marriages” should be eliminated, and they readily passed a revised form of Lord Lyndhurst's bill, declaring that all marriages within the prohibited degrees of affinity contracted before August 31, 1835 were immediately and absolutely valid. Yet, even as they eased restrictions on existing marriages, they tightened the law for the future by adding a clause which made marriages of both affinity and consanguinity contracted after that date absolutely void.
In the parliamentary debate on the bill, there was some opposition from those who argued that marriages within certain degrees of affinity, in particular a man and his deceased wife's sister, should be permitted.