Given that the UK represents one of the largest net contributors to the EU budget, Brexit is likely to have a significant impact on the contributions of all Member States, including Ireland’s. The exact impact will dependent on the nature of the final agreement between the EU and the UK regarding its involvement with the EU budget post-Brexit.
Under the Withdrawal Agreement between the EU and UK, the UK had agreed to continue to pay into the EU budget for the remaining years of the current MFF, as if it was still a member. This would result in no additional impact on Ireland’s contributions or receipts up to the end of the current Multiannual Financial Framework (MFF) in December 2020.
However, if that Withdrawal Agreement is not concluded and there is a no-deal Brexit, the impacts on the EU budget will need to be clarified. Under this scenario the UK would need to clarify its intentions regarding whether it still intended to continue making payments towards the current MFF.
The European Commission has proposed a number of legislative proposals to prepare for the UK's withdrawal. The EU-level measures are summarised in the European Commission’s fourth Brexit Preparedness Communication of 10 April 2019 and includes a measure for the 2019 EU budget, which establishes a legal basis for the UK to continue to both make payments into the EU budget and to access receipts from it for the year 2019. This framework seeks to minimise any unnecessary disruption for beneficiaries of EU spending programmes at the time of withdrawal.
If the UK decided not to continue with EU budget payments, then both the Commission and Member States would need to consider the most appropriate way forward. However, the gap would need to be mitigated by either increased contributions from other Member States, reductions in EU funding programmes, or a combination of both.
My Department monitors and analyses the potential impact of Brexit on our EU budget contributions on an ongoing basis. This analysis is based on the best information and data available at the time in question. As a result, for Budget 2020, my Department will be updating its forecasts in the run up to Budget day.
It should be noted, that the Commission’s proposal for the next MFF 2021-2027 (published, May 2018) is based on the UK no longer contributing to the EU budget, and as such, incorporates the impact of Brexit.
As you can appreciate, I don't want to engage in speculation, given the sensitivity around Brexit.