RTE reports

  • EU will issue a letter to the British government
  • Letter will spell out a series of reassurances on the Irish backstop
  • Letter will stress that backstop is not the EU's preferred solution to avoid hard border
  • Letter will insist that there can be no renegotiation of the backstop

The report can be found here. In short, the letter basically doesn't change a single thing ahead of tomorrow's vote in parliament. As mentioned before, all that is being offered by European leaders are "clarifications" of the current withdrawal agreement. They are nothing near legally-binding assurances so it isn't going to sway parliament's view of May's deal.