Can EU countries limit national civil service jobs to national citizens, or do any EU citizens have a right to work in any EU national civil service?

Question

In some countries, national civil service employment has nationality restrictions. For example:

• In Germany, the civil servant must be German or be an EU national (source). However, someone told me that in the recent past, only German nationals could be civil servants.
• In the United Kingdom (pre-Brexit), civil servants must have the nationality of the UK, Ireland, Switzerland, Turkey, a Commonwealth State, or a EEA state (source).
• In Belgium, the national civil service is open to Belgians, EEA nationals, or Swiss nationals (source).

Is there a general EU rule that implicitly or explicitly means that any EU national is eligible to work for (most) jobs in the national civil service of other EU countries? This article which states that EU national civil servants will not lose their right to work as UK civil servants post-Brexit appears to imply that this right is currently derived from their EU nationality, but does not expilictly say so.

I'm aware that some particular roles, such as spy or soldier or President, may have specific nationality requirements, but in this question I'm interested in the general case.

Answer 1

Yes, they can. See the latest consolidated version of the TEU and TFEU, Article 45(4) TFEU (emphasis added):

TITLE IV

FREE MOVEMENT OF PERSONS, SERVICES AND CAPITAL

CHAPTER 1

WORKERS

Article 45

(ex Article 39 TEC)

1. Freedom of movement for workers shall be secured within the Union.

2. Such freedom of movement shall entail the abolition of any discrimination based on nationality between workers of the Member States as regards employment, remuneration and other conditions of work and employment.

3. It shall entail the right, subject to limitations justified on grounds of public policy, public security or public health:

   (a) to accept offers of employment actually made;

   (b) to move freely within the territory of Member States for this purpose;

   (c) to stay in a Member State for the purpose of employment in accordance with the provisions governing the employment of nationals of that State laid down by law, regulation or administrative action;

   (d) to remain in the territory of a Member State after having been employed in that State, subject to conditions which shall be embodied in regulations to be drawn up by the Commission.

4. The provisions of this Article shall not apply to employment in the public service.