Legally, according to Geoffrey Robertson, a barrister who is Master of the Bench at Middle Temple (probably makes him pretty much an expert then) Article 50 is not just invoked. It states that 'A member state may decide to withdraw from the Union in accordance with its own constitutional requirements'. As our constitutional requirements do not allow for decision making by referendum, any referendum is advisory only - this one has advised Parliament that the country is pretty much split down the middle. In order to leave the EU, MPs must first repeal the 1972 European Communities Act. If an MP thinks that it is in the country's best interest to stay in the EU, they have a duty to vote against repealing the act, and if they think it is in the country's best interests to leave, they have a duty to vote the opposite way. Article 50 will only be deemed to be invoked if the Act is repealed. So, whatever way you want this to go, the best way to make it happen is to lobby your MP (always supposing you've actually still got one after all these shenanigans).