ECO's Special Report Pegs the Linha Circular at €380 Million for 2 km of Tunnel — Inside the 80% Cost Blowout, the Four Revisions Since 2018, and the 30-Month Delay Pinning Lisbon's Metro to Q2 2026

Two kilometres of underground track between Rato and Cais do Sodré, two new stations at Estrela and Santos, and a project that left the drawing board in 2018 priced at €210 million. The bill that landed on Conselho de Ministros desks on 16 April 2026 took that figure to €380 million, an 80% overrun on the original envelope and €170 million above where the line stood when contracts were signed. ECO's especial on Saturday, 25 April, takes the now-canonical question — "onde foi parar o dinheiro?" — and walks line by line through eight years of revisions. The conclusion is uncomfortable for both the previous Costa-led PS government, which approved the largest single jump, and the current Montenegro Executive, which has signed off on the latest tranche while pointing the finger backwards.

The €48 million top-up that pushed the total past €380 million

The trigger for the new public scrutiny is a Conselho de Ministros authorisation issued on 16 April 2026. The Government cleared an additional €48 million for Metropolitano de Lisboa to finish the Linha Circular — formally the closure of the Yellow and Green lines between Rato and Cais do Sodré, with new stations at Estrela and Santos. That €48 million takes total committed investment to €380 million on a project that began life in 2018 with a €210 million envelope and a December 2023 inauguration date. The current operational plan targets Q2 2026, a 30-month slip on the original schedule.

Minister of the Presidency António Leitão Amaro told reporters after the Conselho de Ministros that "o acréscimo dos tais 80% foram decididos em 2022" — that the bulk of the cost increase was approved under the previous Government, not the current one. The political point is that the latest €48 million is a residual, not the main story; the main story is the €170 million in revisions that piled up across four separate amendments before April 2026.

The four revisions, year by year

The Linha Circular envelope has now been revised four times since the original 2018 launch:

• 2018 — €210 million. Initial budget for the Rato-Cais do Sodré closure plus Estrela and Santos. December 2023 deadline.
• Successive 2020-2022 revisions to €331.4 million. A 58% deviation from the original envelope, driven by ground conditions encountered in tunnelling, cost inflation on civil-engineering inputs, and design changes around station layouts.
• April 2026 — €380 million. The latest €48 million top-up, the fourth revision, takes the total to 80% above the 2018 figure.

Per kilometre of new tunnel, that is roughly €190 million — a unit cost that puts the Linha Circular near the top of European urban-metro extensions of comparable length.

How the project sits inside Metro de Lisboa's wider €500 million deviation

In October 2024, then-Secretary of State for Mobility Cristina Pinto Dias was already telling Parliament that across three Metro de Lisboa expansion projects — the Linha Circular, the Linha Vermelha extension to Alcântara, and the Linha Violeta in Loures-Odivelas — combined timetables had slipped 18 to 30 months and budget deviations were running near €500 million. The Linha Circular is the largest single contributor to that figure and the closest to inauguration, which is why it has become the lightning rod for the wider story.

The Loures-Odivelas Linha Violeta cleared a Brussels concession review on 21 April 2026 only after the Mota-Engil-led consortium swapped its Chinese partner; that political clearance does not address its own escalating cost line, which is being tracked separately. The Linha Vermelha extension to Alcântara remains under environmental review.

What the €380 million actually buys

The Linha Circular, when it opens, will not extend the Metro by 2 kilometres in the conventional sense. It closes a gap. From Q2 2026, the Yellow line currently ending at Rato will instead curve south through Estrela and Santos to terminate at Cais do Sodré, joining the Green line. The result is a circular route — Saldanha-Marquês de Pombal-Rato-Estrela-Santos-Cais do Sodré-Baixa-Chiado-Restauradores-Anjos-Saldanha — that turns two radial lines into a fully connected loop through Lisbon's centre and southern slope down to the Tagus.

For commuters, the practical change is that travel between Rato and Cais do Sodré, currently a multi-leg journey via Baixa-Chiado, becomes a one-stop ride. Estrela station serves the Basílica and Jardim and the Assembleia da República's western flank; Santos station serves the riverfront art district and connects to the suburban Cascais line at Cais do Sodré.

Why the cost ran away

Three drivers dominate the public record on the cost increases. The first is geological: the section between Rato and the Tagus runs under dense urban Lisbon with old water tables and unstable substrata, and several tunnel sections required reinforced lining and dewatering systems not anticipated in the 2018 design. The second is inflation on construction inputs — concrete, steel, electrical equipment — that ran 25-40% above 2018 forecasts during 2021-2023. The third is design change: the Estrela station was reconfigured during execution to accommodate accessibility requirements and connection corridors that increased excavation volume.

Leitão Amaro's argument is that the largest tranche of those revisions — the move from €210 million to roughly €331 million — was authorised in 2022 under the previous government, before the current Executive took office in March 2024. The opposition's counter-argument, advanced by Chega on 20 April when it announced it would question the Government and admitted the possibility of a parliamentary inquiry, is that the €48 million now being added in 2026 is itself an admission that the contract management has remained inadequate under the current Government.

The wider fiscal picture: defence, PRR, and the squeeze on capital spending

The Linha Circular row arrives in a budget environment where Portugal is simultaneously committing to step-changes in defence spending — the 5%-of-GDP NATO target by 2035 locks in over €3.84 billion in 2026 alone — and watching its PRR execution drift below 50% with a hard August 2026 deadline. Capital spending headroom is finite. Every additional €48 million absorbed by an existing infrastructure overhang is €48 million not available for the next project on the list, whether that is a Cascais line modernisation, a Braga BRT, or the Lisbon Violet extension.

For Metro de Lisboa as an operator, the larger story is whether the Q2 2026 inauguration holds. Three months separate the latest authorisation from the operational deadline, and station fit-out, signalling commissioning, and the regulatory testing required before passenger service typically need a longer lead time than that. If the Linha Circular slips again, even by a month, the Q2 commitment becomes a Q3 reality — and the question of how a €380 million project closes its books shifts from political debate to operational delivery.

Sources: ECO especial "Onde foi parar o dinheiro?" (25 April 2026); Conselho de Ministros communiqué (16 April 2026); RTP, Observador and Jornal Económico coverage of the €48 million authorisation; Parliament Q&A with Secretary of State Cristina Pinto Dias (October 2024).